Deliverability insights
Honest, practical writing on inbox placement, authentication, and the tools that actually matter. No fluff, no SEO padding.
Course Platform Emails: Teachable, Thinkific, GetCourse Deliverability
Course-platform emails are sent from the platform's IP pool. Inbox rates vary widely. The custom-domain (CNAME) options at Teachable, Thinkific, and GetCourse — and what to test.
Zoom/Google Meet Invite Emails: Do Calendar Invites Bypass Spam?
Calendar invites (.ics) get auto-added to many users' calendars regardless of spam status. Why that's the most underused 'always delivers' channel for events.
Event Ticket Emails Not Received: Eventbrite, Luma, Timepad Deliverability
Eventbrite, Luma, Timepad all send tickets from their own domains. Eventbrite inboxes around 92%, Luma higher, Timepad weaker — what to do as an organizer.
Webinar Confirmation Emails in Spam: 30% No-Show Rate Explained
Industry no-show baseline is 50-60%. A chunk of that is just the registrant forgetting — but a measurable slice is the confirmation+reminder hitting spam.
In-App Notification vs Email: When Email Fails, Does Your App Have a Backup?
If 5% of users miss your email and 5% miss your push, the overlap is the silent failure. Why dual-channel notifications need a delivery audit on both legs.
SaaS Onboarding Emails: The First 7 Days Decide Retention
Day-0/1/3/7 emails set the retention curve. If they hit Promotions or Spam, you lose users who never even see your product story. The 7-day plan + deliverability angle.
Product Update Emails: Changelog That Nobody Sees
Changelog emails are low-engagement, high-volume, and easy to land in Promotions or Spam. Why this matters for product adoption — and the simple fix.
Trial Expiration Emails in Spam: You're Losing Conversions and Don't Know It
If 15% of your trial-end emails land in spam, you lose 15% of your potential conversions silently. The diagnostic, fix, and seed-test cadence for trial sequences.
KYC Verification Emails Not Arriving: How Fintech Loses Customers at Onboarding
30-50% drop-off at KYC step in fintech. Some of that is friction, some is documents-pending emails landing in spam. The deliverability slice of the KYC funnel.
Payment Processor Emails: Stripe vs PayPal vs Square Deliverability
Stripe receipts inbox 99%+. PayPal sometimes hits Promotions. Square varies by region. Why the receipt sender choice matters for chargebacks and customer trust.
Bank Transaction Alerts Going to Junk: Compliance and Security Risk
When the 'unusual login' alert lands in junk, a customer misses a fraud event. For banks this is a compliance gap. The deliverability + risk angle of bank notifications.
OTP and Verification Code Emails in Spam: The Fintech Nightmare
When your 6-digit OTP lands in spam, the user can't log in, files a chargeback, or churns. Why fintech OTPs hit spam more than any other transactional email.
Multi-ESP Setup: How to Split Marketing and Transactional Without Breaking Deliverability
Mixing transactional and marketing on one IP poisons your password-reset emails when a campaign goes wrong. The split: separate ESPs, separate subdomains, separate authentication.
Domain Change and Email: How Rebranding Affects Deliverability
A rebrand to a new domain restarts your reputation. The 90-day plan to keep deliverability while you transition From: lines, DNS, and brand identity.
Moving From Shared IP to Dedicated: The Warm-Up You Can't Skip
A dedicated IP starts at zero reputation. The 4-week ramp from your existing shared-IP volume — and why most migrations fail at week 3.
Mailchimp to Brevo Migration: Deliverability Pitfalls and How to Test
Mailchimp's reputation is yours alone, Brevo's is shared with their pool. Migrating means new IP, new sub-IP rotation, new authentication. The specific Mailchimp→Brevo gotchas.
Switching ESPs Without Killing Deliverability: The Migration Playbook
A naive cutover from one ESP to another tanks inbox rate for 4-6 weeks. The graduated migration playbook: dual-send, IP warmup, DNS staging.
Tax Season Email Deliverability: Accountants and Financial Services
January-April sees accountants drowning their clients in 'send your W-2' reminders. Filters react: financial keywords + attachment risk = spam. The tax-season playbook.
Back to School Emails: Education Sector Deliverability Guide
Education senders hit volume spikes in late July through August. Edu domains get extra filter scrutiny. The deliverability rules specific to schools, ed-tech, and tutoring.
New Year Email Campaigns: Warm Up Before the Rush
January 2nd through 7th sees the year's largest cold-email surge. If you start sending then with a cold domain, you fight every other sender for attention. Warm in December.
Holiday Season Emails: Why December Is the Hardest Month for Inbox
Volume across all senders triples in December. Filters get stricter. Engagement drops. Why the inbox is hardest 12-15 to 12-26 — and how to plan around it.
Black Friday Email Deliverability: Pre-Campaign Checklist
BFCM volumes 5-10x normal. Without warm-up, segmentation, and a seed-test rehearsal in October, your Cyber Monday email lands in Promotions or worse.
Purchased Email Lists: Why They Destroy Deliverability (With Data)
Bought lists carry 30-60% bad addresses, violate GDPR/CAN-SPAM/CASL, get ESP accounts banned within hours, and cost months to recover from. The full math, plus legitimate alternatives.
Re-Engagement Campaigns: How to Reactivate Dead Contacts Without Hurting Deliverability
A blast to dormant contacts can crash reputation overnight. The safe playbook: stratify by inactivity, send small batches from a separate identity, single attempt only, ruthless suppression.
Spam Traps Explained: How One Bad Address Ruins Your Domain
Pristine, recycled and typo traps — who runs them, how they enter your list, why verifiers can't catch them all, and why a sunset policy is the only complete defence.
Email Verification Services Compared: ZeroBounce vs NeverBounce vs Bouncer
Honest comparison of the four major verifiers — coverage, catch-all handling, EU/GDPR posture, false-positive rates and which to use for which job.
Email List Hygiene: Why Cleaning Your List Improves Inbox Placement
A clean 50K list out-delivers a dirty 100K every time. The hygiene playbook: bounce handling, suppression, sunset policies, complaint feedback loops, segmentation by engagement.
Email Subject Line and Spam: Do Caps and Emojis Hurt Deliverability?
All-caps still costs 8-12% inbox placement. One emoji helps, three hurts. Faking RE: prefixes is detected. The real subject-line rules backed by seed-mailbox testing.
Attachments in Email: PDF, DOCX, ZIP — Which Triggers Spam?
The risk hierarchy from blocked-outright (.exe) through password-protected ZIP penalties to generally-safe PDF — and why cloud links beat attachments for cold outreach every time.
Links in Email: How Many Is Too Many for Spam Filters
Filters score every link's domain reputation, redirect chain, and anchor mismatch. Why 5 clean links beat 2 dirty ones, and why generic shorteners and shared trackers cost you placement.
Image-to-Text Ratio in Email: Does It Still Affect Spam Filters?
The 60/40 rule is dead but the principle survives. Modern filters OCR your images, score alt text, penalise image-only emails — and the working ratios for B2B and B2C in 2026.
HTML Email vs Plain Text: Which Gets Better Inbox Placement?
Plain-text-only is a 2008 myth and HTML-only is suspect. Multipart/alternative with both parts properly populated is the modern baseline — here's the spec, the rendering rules and the test data.
Spam Trigger Words 2026: Which Still Matter and Which Are Myths
Modern Bayesian and ML filters score sender reputation, engagement and link quality far more than vocabulary. The handful of words that still hurt — and the long list of myths — explained with real test methodology.
I'm on 5 Blacklists at Once: Triage Guide (Which to Fix First)
Multi-list listings almost always share one root cause. Triage by impact — Spamhaus and Microsoft first, Barracuda and SpamCop next, niche RBLs last — with a time-cost vs impact matrix and signals for when to give up on a domain.
Microsoft SNDS: How to Check and Fix Your IP Reputation With Outlook
Microsoft SNDS gives per-IP daily reputation data nobody else can see — registration via TXT record, the Green/Yellow/Red colour codes, fixing Red status, JMRP feedback loop, and why SNDS doesn't cover Office 365.
UCEProtect Blacklist: The Controversial List That Blocks Entire Subnets
UCEProtect Level 1/2/3 explained, with the collateral-damage problem of Level 3 listing entire ASNs, the €15 paid express delisting option, and a pragmatic view on which receivers actually query Level 2/3.
Spamcop Blacklist Removal: Why It's Automatic (and Why That's a Problem)
SCBL listings auto-expire 24h after the last spam report — so there's no removal form. Explains the re-listing trap caused by forwarding loops, seed traps and reporting users, and the detective work that breaks the cycle.
SORBS Blacklist: How to Delist and Prevent Re-Listing
SORBS sub-lists (DUHL, SPAM, ZOMBIE, OPEN-RELAY) explained, with historical delisting workflow and a candid note that Proofpoint sunset SORBS in mid-2024. Covers what 2026 SORBS-attributed bounces actually mean and the modern equivalents.
Barracuda Blacklist Removal: Request Form + What to Fix First
Barracuda BRBL blocks at thousands of business mailboxes. Walks through the removal request form, what to write in the explanation, and what list-quality / authentication issues to fix before submitting.
How to Delist From Spamhaus: Step-by-Step (SBL, XBL, PBL)
Spamhaus delisting playbook by list type — SBL needs a manual form with evidence, XBL is automatic via CBL self-service, PBL is ISP-controlled. Includes the lookup tool, what evidence to prepare, and realistic 24-72h response times.
Domain Warmup Failed: Signs, Causes, and How to Restart
Symptoms of a failed warmup, the five most common root causes, and the rules for deciding whether to recover the damaged domain or restart on a fresh one.
Buying a Used Domain for Cold Email: How to Check Its Reputation First
Used domains carry their old reputation. The full due-diligence checklist: WHOIS history, Wayback, SecurityTrails DNS, blacklists, and a probe-with-control before paying.
How to Test If Your Warmup Actually Worked (Seed Test After Warmup)
Why warmup tools' self-reported numbers lie, and how to verify with three staggered seed tests against 20+ real provider mailboxes before launch.
IP Warmup for Dedicated Senders: Volume Ramp-Up Schedule
A real day-by-day volume schedule for warming a dedicated IP, with per-provider caps for Gmail, Outlook, Yahoo, and recovery rules when 4xx deferrals appear.
Domain Age and Deliverability: How Long Until Gmail Trusts You
Why WHOIS age is a myth and what Gmail actually tracks. Real reputation milestones at days 30, 90, and 180, plus what bends the curve.
Unsubscribe Link: Legal Requirements by Country (US, EU, CA, UK, RU)
Every country requires unsubscribe — they disagree on speed, format, and link lifetime. A side-by-side reference for global senders, plus the RFC 8058 one-click rule that beats them all.
Can You Legally Send Cold Email in EU? GDPR + Legitimate Interest Explained
B2B cold email in the EU lives in a narrow legitimate-interest lane — and disappears entirely in Germany. How to write a balancing test that actually holds up at a DPA.
152-ФЗ и рассылки: как соблюсти закон о персональных данных в email
Email-адрес — это уже персональные данные. Согласие, локализация в РФ, уведомление Роскомнадзора и штрафы по ст. 13.11 КоАП до 18 млн рублей за повторные нарушения.
CASL: Canadian Anti-Spam Law for Email Senders (Practical Guide)
Canada's anti-spam law is the strictest in North America: opt-in by default, 2-year implied-consent window, and CRTC penalties up to CAD $10M per violation for businesses.
GDPR and Email Marketing: Consent, Deliverability, and the Fine Print
GDPR is a data-protection law that quietly governs every email campaign. Lawful bases, consent vs legitimate interest, soft opt-in, and how privacy posture moves your inbox rate.
CAN-SPAM Act 2026: What Email Senders Must Do (and What Most Get Wrong)
The US CAN-SPAM Act in plain English: required disclosures, the 10-business-day opt-out clock, and the $50,120-per-email penalty most senders forget exists.
Email Is Not Dead — Your Metrics Are
Every year someone declares email dead. Every year email outperforms the channel that replaced it. The thing that died is the honesty of the metrics we used to measure email.
The CMO Who Killed Their Email Team's Dashboards and Saw Revenue Go Up
A composite story from half a dozen conversations: what happens when you turn off the open-rate dashboards and force a team to use only placement, replies and pipeline.
Why Most Email Marketing Agencies Are Selling You Vanity
A provocation: the email agency industry has quietly become a vanity-metrics machine. What you are paying for, what you are actually getting, and what you should demand.
Apple Mail's Opaque Filtering: Probing Without Feedback Loops
Apple has no Postmaster, no FBL, no reputation dashboard, no complaint feed. Here's how to reverse-engineer Apple Mail placement with only indirect signals.
Microsoft SNDS and Why Most Senders Misread It
SNDS is a green dashboard that hides a red problem. Four reasons senders misinterpret Microsoft's smart network data, and what to do instead.
Gmail Postmaster Tools: What It Shows and What It Hides
Google's Postmaster dashboard is the closest thing Gmail gives you to ground truth. It is also silent on the three things that matter most. Here is the map.
Engagement-Seconds: How Long Users Actually Spend in Your Email
Opens tell you zero. Clicks tell you barely more. Engagement-seconds — how long a human's eyes are on your message — is the quality metric nobody reports.
Inbox-Placement-Rate: The Metric Inbox Check Was Built For
Delivery rate says 99%. Placement rate says 61%. The gap is where your revenue disappears. How IPR is defined, measured and reported.
Pipeline Attribution Beats Open Rate for B2B Email
Open rate tells you nothing about revenue. Pipeline attribution does. How to wire email to opportunities, why CRMs get it wrong, and the minimum viable setup.
Reply Rate: The One Email Metric That Cannot Be Faked
Opens lie. Clicks lie. Replies don't. Why reply rate is the only email metric that survives MPP, security scanners and LLM summarisers — and how to instrument it.
Is CTR still usable for B2B campaigns? A nuanced take
If scanners, proxies, and wrappers corrupt clicks, is CTR dead for B2B? Not quite. Here is when it still helps, when it lies, and how to use it responsibly.
What Apple Mail v16 changed about click reporting
Mail Privacy Protection phase 2 quietly changed what Apple Mail does to links on open. Here is the short list of changes and what they mean for your CTR.
Unique clicks vs total clicks: why both are lies
The unique/total dichotomy hides more than it reveals. Here is why both numbers are misleading and what engagement metric actually holds up.
Microsoft Defender link-click pattern analysis: a signature guide
Defender for Office 365 has its own click signature — different from SafeLinks alone. Here is how to fingerprint Defender traffic in your ESP logs.
Why click events in ESPs lag inboxing by hours
A click is not inbox delivery. Corporate archival, search indexing, delayed rendering, and shift-work recipients turn clicks into a lagging indicator.
Link-tracking wrappers break with every email client update
Outlook, Apple Mail, Gmail Android, Thunderbird, Spark — each update breaks or changes click tracking in subtle ways. A living compatibility matrix.
Your 30% CTR is really 9%: here is the math
A walkthrough of how a real B2B campaign with a reported 30% CTR reduces to 9% real human CTR after filtering scanners, proxies, and pre-fetches.
Bot clicks from security scanners: a field guide to spotting them
Barracuda, Proofpoint, Mimecast, Cisco and dozens of smaller gateways click every link. Here is how to identify scanner traffic in your click logs.
Gmail Image Proxy: why it distorts opens AND link tracking
Gmail proxies every image and now pre-fetches some links as well. Here is how that changes your open and click numbers and what to trust instead.
Outlook SafeLinks inflates your CTR by 20-40% (and how to prove it)
Microsoft SafeLinks rewrites every URL and scans it before a human ever sees the email. Those scans count as clicks. Here is how to measure the real CTR.
Open Rate Is a Vanity Metric: The Executive-Level Replacement
For boardroom reporting, open rate is indistinguishable from noise. A concise framework for CMO-level email metrics in 2027: one headline, three diagnostics, one summary score.
Why Your ESP's Open Rate Dashboard Lies (And Exactly How Badly)
We audited seven major ESPs and measured the gap between their reported open rate and a humans-only estimate. The gaps ranged from 2x to 6x — per-vendor breakdown inside.
The Case for Deleting Open Rate From Your Weekly Report
A four-week plan for removing open rate from the Monday morning report — plus a script for the conversation with leadership when the familiar number disappears.
Open Rate vs Inbox Placement: Side-by-Side, Same Campaign
We measured both open rate and inbox placement on the same 150-campaign sample. The two metrics disagreed 61% of the time. Here is when each one was right.
Why iOS 15 Killed Subject-Line A/B Testing (And What to Do Instead)
A/B testing subject lines by open rate has been statistically meaningless since September 2021. Here is the maths of why, and the modern click-based alternative.
What a Good Marketing Team Replaces Open Rate With
If open rate goes, what goes on the dashboard? A practical replacement stack of four metrics that survive proxy pre-fetch and scanner noise.
"98% Open Rate" Claims in Outreach Tools: How to Read the Fine Print
Cold-email vendors love to publish case studies with absurd open rates. Here is a buyer's checklist for spotting the tricks that produce those numbers.
Gmail, Outlook, Apple Mail: How Each One Breaks Open Rate Differently
All three mailbox providers distort open rate — but in opposite directions. Apple inflates, Outlook suppresses, Gmail does both. Provider-by-provider guide.
The Anatomy of a Fake Open: What a Pre-Fetched Pixel Actually Tells You
We recorded the raw HTTP requests behind 100,000 reported opens. Less than a third came from humans. Here is the packet-level breakdown by source.
Open Rate Is Dead in 2027: A Post-Mortem of Email Marketing's Favourite Metric
Six years after Apple Mail Privacy Protection, open rate is still on every marketing dashboard — and still meaningless. Here is the forensic case for retiring it.
How to Pitch Deliverability Investment to a Skeptical CEO
A battle-tested pitch script for CEOs who see deliverability as an operational detail rather than a strategic risk. Script, objection handling, and the single chart that closes the meeting.
Deliverability Is a Growth Lever: Here Is the DCF Model
A working discounted cash flow model that treats inbox placement improvements as a capital project. Assumptions, sensitivities, and the output sheet finance will accept.
From Vanity to Value: An Executive's Rewrite of the Email Scorecard
A line-by-line rewrite of the typical marketing email scorecard, replacing vanity metrics with value-anchored measures an executive can actually act on.
Marketing Ops Maturity Curve: Where Does Inbox Monitoring Sit?
A five-stage marketing ops maturity model with inbox monitoring placed honestly across the curve — and the signals that you are ready to move up.
Building Deliverability Into OKRs: A Template
A copy-ready OKR template that places inbox placement at the objective level, with KRs that force operational discipline without drowning the team in metrics.
The Psychological Trap of "Delivered" Dashboards
Why the "99.8% delivered" headline on your ESP dashboard is the single most damaging piece of confirmation bias in marketing ops — and what to replace it with.
The Cost of Invisible Churn: The Email-Placement Angle Nobody Models
Placement failures create a specific, modelable form of invisible churn. A framework for quantifying it and why it probably exceeds your visible churn number.
Deliverability as a Board-Level Metric: Presenting the Case
What belongs on a board slide, what does not, and how to earn deliverability a permanent line in the quarterly pack without drowning directors in jargon.
Why Your CFO Should Care About Inbox Placement: Revenue per Email
Translate inbox placement into CFO-friendly language: revenue per email sent, gross-margin impact, and why placement belongs in the finance view.
The Executive ROI Case for Deliverability Monitoring
A CMO-ready ROI model for inbox placement monitoring: inputs, math, payback period, and the single chart that closes the budget conversation.
Small E-commerce Email Deliverability: Abandoned Cart & Order Updates
For a $40k/month Shopify store, 1% inbox-placement drop on order confirmations and cart recovery can be $4k of lost revenue. The playbook for small e-commerce.
Financial Advisor Email Deliverability: Portfolio Reports & Compliance
Quarterly statements, portfolio updates, compliance disclosures. Why financial-advisor email lives under SEC/FINRA rules and still has to clear spam filters.
Insurance Email Deliverability: Policies, Renewals & Claims
Policy documents, renewal notices, claims status updates. Why insurance emails trip phishing filters and the playbook for independent agents and agencies.
Education Email Deliverability: Admissions & Parent Notifications
A missed admissions-decision email loses a student. A missed snow-day notification means parents sending kids to a closed school. Playbook for schools and universities.
Nonprofit Email Deliverability: Donors, Appeals & Receipts
Year-end giving, donor newsletters, emergency appeals, and tax receipts. The deliverability playbook for nonprofits running on lean tech budgets.
Recruiter Email Deliverability: Candidate Outreach & Offer Letters
Recruiters live at the edge of cold-email policy. When the pitch lands in spam, the candidate never replies, and the close-rate story looks like a sourcing problem.
Bookkeeper Invoice Deliverability: Cash Flow vs Spam Filters
For a one-person bookkeeping practice, a week of undelivered invoices is a month of delayed cash. A deliverability playbook for bookkeepers and solo accountants.
Healthcare Email Deliverability: Appointment Reminders & HIPAA
Appointment reminders, no-show rates, HIPAA constraints, and the narrow band of email you can actually send from a clinic. A deliverability playbook.
Law Firm Email Deliverability: Client Updates & Billing
A single undelivered billing statement is a collections problem. A missed discovery deadline is malpractice. The email deliverability playbook for law firms.
Real Estate Agent Email Deliverability: Listings & Showings
Listing alerts, showing confirmations, open-house invites. Why agent emails land in Promotions or Spam, and the deliverability playbook for brokerages of every size.
The 10-Minute Weekly Deliverability Health Check
A tight five-item weekly routine that catches 90% of deliverability issues before they become fires. Takes ten minutes every Monday.
Renew Your SPF/DKIM/DMARC Once a Year — A Calendar Reminder
DNS authentication records drift silently. A once-a-year review prevents the outages they cause. Here is exactly what to check, and when.
Moving ESPs? The Before, During, and After Checklist
A practical ESP migration checklist for non-engineers. Thirty items across three phases so the new ESP performs as well as the old one.
After a Rebrand: The Deliverability Task You Forgot
A new name, new domain, new logo — and an unwarmed sending identity that your best customers now see as spam. The post-rebrand email playbook.
The Marketer's Q1 Deliverability Checklist
Eleven items to close out in January so your email program lands the rest of the year. A checklist for the person who owns the calendar, not the DNS records.
The Cost of Bad Deliverability — A Back-of-Envelope Calculator
A simple calculator that turns inbox placement percentage into a dollar figure. Numbers for cold outreach, transactional, and B2C marketing.
When to Escalate a Deliverability Problem: A Decision Matrix
A four-quadrant decision matrix for non-technical operators: ignore, monitor, internal fix, or escalate externally. With thresholds and examples.
Before You Hire a Deliverability Consultant, Try This First
Consultants are great for hard problems. Most deliverability problems are not hard — they are unexamined. Here is the pre-consultant checklist.
Quarterly Email Health Review — A Calendar Template
A four-meeting, 45-minutes-each calendar template to keep your email program healthy without hiring a deliverability consultant.
Run a Deliverability Audit in 30 Minutes (No Technical Skills)
A step-by-step 30-minute audit for founders and marketers. Six checks, one free tool, and a one-page output your engineer can actually act on.
If You Can Only Do One Thing to Improve Deliverability, Do This
A single high-leverage action that improves deliverability more than any other for small-team founders. No DKIM, no dedicated IP, no $3k consultant.
Fix Deliverability Without Hiring a Consultant: A 2-Hour DIY Plan
Deliverability consultants charge $2–5k for work a small-team founder can do in two focused hours. Here is the DIY plan that covers the 90% case.
The Founder's Deliverability Playbook — No DKIM Deep-Dives, Just Priorities
You don't need to understand DKIM key rotation. You need to know which five things matter and in what order. The small-team founder's playbook.
Your Emails Just Stopped Arriving — A Monday Morning Guide
It is 9am Monday. Your emails aren't landing. Customers are complaining. You need to triage fast. Here is the non-technical founder's order of operations.
5-Minute Broken Campaign Checklist (No Technical Knowledge Required)
Campaign not working? Before you call a consultant, run this five-minute checklist. No DNS, no headers, no jargon — just seven clicks that tell you where the problem is.
Cold Outreach Is Down Across the Board — Is It You or Deliverability?
The collective wisdom on LinkedIn is that cold email is dead. The data says it is harder, not dead. Here is how to tell whether the slump is macro or you.
When Silence Means Spam, Not Disinterest: A Diagnostics Checklist
Before you rewrite your copy, rewrite your ICP, or quit outbound, run this ten-minute checklist. Silence is often a deliverability problem in disguise.
Reply Rate Benchmarks by Industry — and What They Hide
Every outreach vendor publishes an industry benchmark report. The numbers are useful only if you understand the four distortions baked into every one of them.
The Quiet Founder Tax: Missed Replies from Bad Deliverability
There is a silent cost to bad deliverability that never shows up on any invoice: the replies you never get. We put a number on the quiet founder tax.
My Outreach Tool Says 95% Delivered — Why That Number Hides Failure
Your dashboard shows 95% delivered and you feel safe. In cold outreach, delivered is a legal status, not a business outcome. Here is what the number actually hides.
Cold-Email Silence Is a Deliverability Signal, Not a Rejection
Silence from a cold sequence usually means one of three things. Only one is not interested. How to diagnose which you're actually seeing.
Why B2B Decision-Makers Never See Your Email
Enterprise buyers live behind the most aggressive filters in email. Microsoft 365, Proofpoint, Mimecast, Barracuda — why cold outreach dies there and what to do.
Smart Send + Smart Content + Zero Replies = Deliverability Problem
If your ESP is optimising send times and your AI is optimising copy and your reply rate is still zero, the bottleneck is not intelligence. It is infrastructure.
The Hidden Cost of a "Sent" Dashboard
A dashboard that optimises for sent optimises for activity, not outcome. The real cost of that metric choice and what executives should ask for instead.
How a Bad Warm-up Silently Kills Your Q4 Pipeline
Warm-up tools look the same and cost the same. The bad ones generate synthetic engagement filters now detect, poisoning your sender reputation before Q4 starts.
Reply Rate Dropped Overnight? This Is the First Thing to Check
A sudden reply-rate collapse is almost never a copy problem or a Monday-morning fluke. The 15-minute triage to find the deliverability cause.
The SDR's Blind Spot: Delivered Is Not the Same as Inbox
Every SDR dashboard lies in the same way: delivered measures SMTP acceptance, not inbox placement. Here is what that gap costs you and how to close it.
Why Your Perfectly Personalised Email Got No Response (Hint: It Was Never Delivered)
You spent 12 minutes researching the prospect. You wrote three perfect sentences. They never saw it. Why personalisation is not a shield against the deliverability funnel.
Your Cold Outreach Works — Your Emails Are Just in Spam
Cold email is not dead. Your emails are probably not bad. They are in the Spam folder, which looks identical to ignored from your dashboard.
I Sent 100 Cold Emails and Got 0 Replies — Here Is What Was Actually Wrong
A founder-friendly autopsy of a 100-email cold campaign with zero replies. Spoiler: the copy was fine. The deliverability funnel was not.
Localhost Email Testing vs Production Inbox Test: Two Different Things
Mailhog/Mailtrap test templates in staging. Inbox-check measures real placement in production. Different problems, different tools — here is when to use each.
Cloud Functions: Email From AWS Lambda, Vercel, Cloudflare Workers
Serverless apps can't run an MTA. SDK-based sending has its own deliverability quirks. Here is the working path per platform, with code.
VPS Email: How to Ensure Your Server's Mail Reaches Inbox
Your $5 VPS can send mail that lands in inbox — if you do the six things outlined here. Postfix, rDNS, DKIM, and a seed test.
Docker + Postfix: Email Deliverability for Containerized Apps
Containerized apps sending mail via Postfix: network, DNS, and DKIM pitfalls in containers — and the Dockerfile that actually works.
Plesk Mail Server: Test Deliverability Before Migration
Before migrating mail to/from Plesk, measure placement. Saves weeks of spam-debugging after cutover — the pre-migration checklist.
cPanel Email: Why Hosting's Built-In Mail Goes to Spam
cPanel's default Exim setup lacks authentication for your domain. Here is the fix for small VPS with cPanel, start to finish.
Readymag / Vigbo / uKit: Russian Builders Email Deliverability
Russian website builders serve Mail.ru and Yandex audiences. Each has its own sending approach — here is the test-then-choose path.
Google Forms Notifications: Do Respondents See Your Follow-Up?
Google Forms sends confirmations from noreply addresses. Follow-up from your Gmail is a different story. Both matter — here is the check.
Tally / NotionForms: Where Do Notifications Land?
Tally and NotionForms handle sending. You can't see headers in their UI. Here is how to verify placement from the outside.
Carrd Forms: The Indie Hacker's Deliverability Problem
Carrd is the indie staple. The form integrations it offers each have their own sender-domain quirks. Here is what to pick, and why.
Framer Forms: Do Leads From Your Landing Page Hit Inbox?
Framer forms route via a service you don't control. Here is how to know whether your startup's landing page is silently leaking leads.
WordPress CF7 vs WPForms vs Gravity: Which Delivers Better?
Same form, three plugins, three deliverability outcomes. Data and a recommendation for admins running WordPress forms in production.
Webflow Forms: How to Check If Leads Actually Arrive
Webflow sends notifications via email. You can't DKIM-sign the sending domain. Here is the test and the Zapier+ESP workaround.
Squarespace Form Submissions: Are They Reaching Your Inbox?
Squarespace locks you out of SMTP. Here is a workaround via Zapier and an external ESP — plus the measurement first.
Wix Forms: The Deliverability Problem Nobody Warns About
Wix handles your form submissions. You don't control the sending domain. Here is how to know if it's hurting you — and what to do.
Tilda Forms: Why Leads Go to Spam (and You Blame Marketing)
Tilda forms send from Tilda's servers. You can't fix SPF or DKIM. But you can measure, then decide — migrate, route, or accept the loss.
Self-Hosted vs SaaS Store: Who Controls Your Email?
The fundamental tradeoff: control vs convenience. Here is what each path gives you for deliverability, and which breaks first at scale.
BigCommerce vs Shopify vs WooCommerce: Which Delivers Emails Better?
Data-driven comparison: the same order confirmation HTML sent through each platform, placement measured across 20 providers.
InSales Email: Guide for Russian Online Stores
InSales runs thousands of Russian stores. Mail.ru and Yandex inbox rules apply strictly — here is the deliverability checklist.
Tilda E-commerce: Forms and Orders — Deliverability Check
Tilda stores rely on Tilda's sending infra. You have limited DNS control. Here is what you can and should do to verify and improve.
Ecwid Notifications: Where Do They Land for Customers?
Ecwid handles sending, but placement depends on your domain. Here is how to verify and improve notification inbox placement.
1C-Bitrix Store: Email for Order Notifications
A Bitrix store-specific deep-dive on order confirmation, shipping notifications, and payment receipt deliverability.
CS-Cart Email: Russian E-commerce Platform Guide
CS-Cart serves Russian and CIS stores. Mail.ru and Yandex have strict rules — here is how to meet them without breaking transactional flows.
PrestaShop Email: SMTP, SPF, DKIM for Store Admins
PrestaShop's built-in mail is limited. Here is the SMTP module + DNS configuration for reliable order emails.
OpenCart: Why Default PHP mail() Kills Your Deliverability
Every OpenCart admin hits this wall. Here is the SMTP extension path and the SPF/DKIM/DMARC setup that actually works.
Magento 2 Transactional Emails: SMTP + Inbox Placement Test
Magento 2 / Adobe Commerce SMTP modules, DKIM configuration, seed testing. The full transactional stack for enterprise stores.
Shopify Email for Store Admins: What You Can and Can't Control
Shopify limits what you can configure. Here is exactly what admins control, what is locked, and the workarounds for inbox placement.
WooCommerce Emails in Spam: Complete Admin Fix Guide
Default WooCommerce sends via PHP mail(). Add WP Mail SMTP, authenticate the domain, seed-test. End-to-end fix for store admins.
SMTP Relay vs Direct Send: Which Gets Better Inbox Placement?
Running your own Postfix vs sending via SendGrid/Postmark/SES: the tradeoffs for real-world inbox placement.
Shared Hosting: Why Your VPS Neighbor Ruins Your Reputation
On shared IPs, another tenant's spam sinks your reputation with Gmail and Outlook. Here is how to tell if you are the collateral damage.
Post-Deployment Email Check: Add to Release Checklist
Every release that touches templates, DNS, or the ESP can quietly regress. A 30-second post-deploy check catches it immediately.
Email Degradation: Spot It Before Crisis
Deliverability does not break overnight; it erodes over weeks. Here is how to spot the slope before it hits a wall.
Detect IP Blacklisting Before Users Notice
Spamhaus, Barracuda, SORBS. Users do not see why; mail just stops landing. Here is how to catch listings in minutes, not days.
DNS Records Your Email Depends On (and How to Monitor Them)
SPF, DKIM, MX, DMARC — each can break silently. Here are the records that matter and how to alert before they cost you mail.
Uptime for Email: Your Website Is Up but Email Is Down
Status-page uptime never shows "email in spam". A $0 monitor can. Here is the concept and the minimum working system.
Nagios / Zabbix / Prometheus: Alert "Emails Going to Spam"
Integrate email placement into the same monitoring stack you already use. Working configs for all three major platforms.
Weekly Deliverability Report: Automate With Cron + Our API
A simple cron job posts weekly placement reports to Slack. Here is the shell, the API call, and the Slack webhook payload.
Email Health Monitoring for Your Website: Set Up in 10 Minutes (Free)
Your website monitors uptime. You should monitor email placement the same way. Here is a 10-minute setup using our free API.
Subscription Renewal Reminders in Spam = Unexplained Churn
Renewal warnings in spam become surprise cancellations labeled as voluntary churn. Here is the measurement gap and how to close it.
Invoice Emails From Your Billing System: Where Do They Land?
Invoices in spam delay payments. Delayed payments hurt cash flow. And nobody in billing is looking at inbox placement. Here is the fix.
Abandoned Cart Emails: Are They Even Reaching Inbox?
Abandoned-cart flows promise big ROI. If half of them land in Promotions or Spam, the ROI is fictional. Here is how to check.
Welcome Emails Nobody Sees: Onboarding Starts in Spam
Users who never see the welcome email start disengaged and churn faster. Here is how to measure and fix onboarding mail placement.
2FA Emails Not Arriving: Users Locked Out of Your App
A 2FA code in spam locks a user out entirely. Here is why transactional flows with urgency get filtered and how to make sure the code arrives.
Payment Receipt: Stripe Delivers but Your Custom Email Doesn't
Stripe receipts arrive. Your custom receipts don't. The difference is ten years of domain reputation — and you can close the gap.
Shipping Notifications in Spam: Customer Calls "Where is My Order?"
Tracking emails that never arrive generate predictable support load. The fix is mostly DNS, a little template hygiene, and continuous measurement.
"I Never Got the Confirmation" — The #1 Support Ticket You Can Eliminate
Every support team sees the same ticket daily. It is always the same root cause. Here is how to kill it at the source.
Registration Emails in Spam: You're Losing 20% of Signups
Email verification in spam = abandoned signups. Nobody complains, they just bounce. Here is how to measure the hidden conversion loss and fix it.
Your App Sends 50 Emails/Day. Do You Know Where They Go?
Every SaaS quietly leaks dozens of transactional emails a day — welcome, reset, 2FA, invoice, invite. Your ESP says "delivered". That is not the same as "in the inbox". Here is the fix.
Order Confirmation in Spam: The Silent Revenue Killer for E-commerce
One missed order confirmation = support ticket + duplicate order + chargeback risk + lost LTV. Here is the economics and the fix, platform-agnostic.
Your Users Aren't Receiving Password Reset Emails. You Just Don't Know It Yet
Missed password resets are the quietest churn in SaaS: users never write a ticket, they just leave. Here is why it is invisible, and the simple monitoring to expose it.
Why You Should Add Seed Emails to Every Campaign (and How to Do It)
Open rate lies, delivery rate lies, spam complaints lag. Seed emails are the only signal that tells you where your campaign actually landed — here is how to add them to every send.
Mailtrap for Staging, Inbox Check for Production: The Missing Half of Your Email QA
Mailtrap catches bugs before production. Inbox Check catches bugs in production. Here is why you need both — and how seed emails on every real send close the loop.
NotiSend: Проверка доставляемости транзакционных писем через seed-тест
Как добавить seed-адреса в рассылки NotiSend и видеть реальное приземление по 20+ провайдерам, а не только delivered-процент из дашборда.
Selzy (ex Sendsay): Email Deliverability + Seed Testing
Selzy reports solid delivery rates but says nothing about Inbox vs Promotions vs Spam. Seed-address testing fills the gap in five minutes per campaign.
eSputnik: Inbox Placement для украинского и CIS-рынка
Массовый инструмент маркетинга в Украине и СНГ. Как добавлять контрольные ящики в рассылку и читать результат по Mail.ru, Yandex, Gmail, Outlook.
Mailganer: Seed-тест перед каждой отправкой
Dashboard Mailganer показывает доставленные, но не показывает где — Inbox, Spam или Promotions. Добавляем seed-адреса в рассылку и видим факт.
Sendsay: Контрольные почты в массовых рассылках
Пошагово: как добавить контрольные адреса в кампании Sendsay и видеть реальный inbox placement по Mail.ru, Yandex, Gmail.
DashaMail: Проверка доставляемости российских рассылок через seed
DashaMail популярен в России, но не даёт inbox placement. Добавляем 5-7 seed-ящиков в рассылку и видим реальный результат по провайдерам.
SendPulse: Seed-тестирование рассылок — пошаговая инструкция
SendPulse отчёты не покрывают inbox placement. Добавляем контрольные адреса в sending list и получаем полную картину по провайдерам.
UniSender: Как добавить контрольные адреса в рассылку
UniSender — один из крупнейших CIS-сервисов. Пошаговая инструкция по добавлению seed-ящиков в кампанию и чтению результата в Inbox Check.
Mandrill (Mailchimp Transactional): Seed Test API-Sent Emails
Mandrill handles billions of transactional sends. Its dashboard reports delivery, not placement. Seed addresses close the blind spot.
Customer.io / Courier: Multi-Channel — Test the Email Leg With Seeds
Multi-channel tools ship push + SMS + email. The email leg is the one that silently lands in spam. Add seed addresses to catch it.
Loops: Product Email for SaaS — Seed Test Your Onboarding Sequences
Loops drives SaaS onboarding and feature emails. If day-1 welcome lands in Gmail Promotions, activation dies. Add seeds to every sequence.
Resend: Modern Email API — Seed Test Your React Email Templates
Resend pairs with React Email for developer-friendly templates. Adding seed recipients takes one array entry and gives you real per-provider placement.
SparkPost (MessageBird): Seed Testing at Scale
SparkPost powers enterprise volume. Dashboards show bounces; seed tests show folder placement. Here is how to bake seeds into every campaign.
Mailgun: API-First Email — Add Seeds Programmatically
Mailgun is API-first; adding seed addresses is three lines of code. Wrap it in your send helper and every outbound call produces a placement check.
Postmark: Transactional Email Seed Testing for Developers
Postmark is known for reliable transactional delivery. But "delivered" is not "inboxed". Add seed addresses on every template and verify.
Amazon SES: How to Add Seed Emails to Bulk Sends
SES is the cheapest ESP at scale. It also tells you the least about where mail lands. Seed addresses on every BulkEmail API call fix that.
SendGrid: Seed Test Your Transactional Emails (Not Just Marketing)
Most guides tell you to seed-test marketing sends. SendGrid transactional needs it more — password resets hitting Spam is a support-ticket nightmare.
Close CRM: Email Sequences + Seed Testing
Close CRM sequences drive sales email at scale. Add seed addresses to every sequence and alert on drops before prospects stop replying.
Snov.io: Drip Campaign Deliverability — Add Seeds Before You Send
Snov.io drip campaigns run unattended for weeks. A single reputation hit can silently kill placement. Seeds on every stage give you a canary.
Hunter.io Campaigns: Seed Test Your Hunter Outreach
Hunter Campaigns is popular for founder-led outreach. Low volume, high importance per send. Seeds verify your first message actually reaches the prospect.
GMass: Gmail-Based Outreach — Seed Test From Your Own Account
GMass sends from your own Gmail account. That means your reputation — not an ESP pool — is on the line. Seed every campaign before volume scales.
Mailshake: How to Test Deliverability Before Your Campaign Goes Live
Mailshake ships campaigns fast. Seed addresses in the test-list let you verify placement before the real recipients ever see the subject line.
Salesloft (Outreach): Enterprise Cold Email — Seed Test Your Cadences
Salesloft/Outreach own enterprise sales email. Cadences run for weeks. Seed a dedicated account into every cadence and you have a continuous placement monitor.
Reply.io: Add Inbox Placement Check to Your Sequences
Reply.io automates multi-channel outbound. Seed addresses in the sequence contact list give you verifiable inbox placement per stage.
Smartlead: Seed Testing With Inbox Rotation
Smartlead rotates senders automatically. A seed that lands in spam on rotation-hop three tells you which account warmed incorrectly.
Woodpecker: Seed Emails for Cold Campaigns — Step by Step
Woodpecker is popular with small teams. Add 5 seeds to every campaign and you know where "replied" rates are really coming from.
Apollo.io: Include Seeds in Your Outbound Sequences
Apollo blends data + sending. Their Deliverability score is aggregate — your seed result is specific. Use both, trust the seeds.
Instantly: How to Seed Test Before Scaling to 1000 Emails/Day
Instantly makes scaling cold outreach easy — too easy. Seed tests on every campaign + rotation account catch the moment reputation starts to slip.
Lemlist: Add Seed Emails to Every Cold Outreach Sequence
Lemlist leans on personalisation to reach inbox. Seed addresses verify the personalisation actually helped — per provider, per campaign.
Flodesk: Beautiful Emails — But Do They Hit Inbox? Seed Test Them
Flodesk designs for creators. Image-heavy templates are Promotions-tab bait. Seed tests tell you when a gorgeous design torpedoed your open rate.
Buttondown: Minimalist Newsletter + Inbox Placement Check
Buttondown skews to indie newsletter writers. Small lists, loyal readers — but spam placement still happens. Seed-test before every send.
Ghost Newsletter: Seed Testing for Independent Publishers
Ghost publishers own their list and their deliverability. Seed addresses are the only no-vendor way to verify inbox placement per issue.
Substack: Can You Even Test Deliverability? (Yes, Here is How)
Substack gives writers little deliverability control. But you can still subscribe seed addresses to your own publication and measure placement.
Beehiiv: Newsletter Deliverability — Are Your Seeds Hitting Inbox?
Beehiiv grew from zero to 750K newsletters fast. Their shared sending pool changes over time. Seed-test every issue to catch pool-reputation drift.
Omnisend: E-commerce Email + SMS — Test Email Leg With Seeds
Omnisend runs both SMS and email for DTC stores. The email leg is where spam happens. Seed addresses on every flow make the problem visible.
Moosend: How to Verify Inbox Placement With Seed Addresses
Moosend is affordable and popular in Europe. Dashboard reports delivered — seeds report where. Add both and you close the loop.
Campaign Monitor: Seed Test Your Branded Emails
Campaign Monitor caters to agencies. Every client send is a brand risk if it lands in spam. Seed addresses catch it before clients complain.
MailerLite: Free Newsletter Tool + Free Inbox Placement Test
MailerLite's free tier is generous. Pair it with our free seed-testing tool and you have a zero-cost stack that still produces real deliverability data.
Drip: E-commerce Email Seed Testing Before Automated Workflows
Drip automates DTC email journeys. A bad workflow burns subscriber trust silently. Seeds on every workflow let you audit placement non-interactively.
AWeber: Inbox Placement Testing With Seed Emails
AWeber is an old guard ESP with a mature reputation system. Seed addresses show you when shared IP reputation shifts affect your deliverability.
GetResponse: Add Seed Addresses to Autoresponders and Newsletters
GetResponse runs autoresponders that touch subscribers for months. A single drift means losing conversions. Seed every step of the autoresponder chain.
Constant Contact: How to Test Inbox Placement of Your Campaign
Constant Contact is one of the oldest ESPs. Their delivery reports are legacy-shaped. Seed addresses give you a modern inbox-vs-spam signal.
Klaviyo: Seed Emails for E-commerce — Test Before Your Black Friday Send
Black Friday is the single worst day to discover your Klaviyo flow lands in Gmail Promotions. Seed-test the flow weeks in advance.
ConvertKit (Kit): Seed Test Your Newsletter Before 10K Subscribers See It
ConvertKit is the creator ESP. One bad send loses trust with thousands. Seeds in a pre-test broadcast de-risk every launch.
ActiveCampaign: Add Inbox Placement Seeds to Every Automation
ActiveCampaign automations run for months. Add seeds to the contact list, watch them move through steps, get real placement data per step.
HubSpot Email: How to Include Seed Addresses in Marketing Emails
HubSpot marketing email is bundled with CRM workflows. Add seed contacts to your send lists and verify before every automation pushes to real contacts.
Seed Testing Your Brevo (Sendinblue) Campaigns: Step by Step
Brevo's newsletter and transactional tiers share a reputation pool. Seed addresses on every send surface pool drift before it costs you opens.
How to Add Seed Emails to Your Mailchimp Campaign
Mailchimp has 12M+ users and still does not expose real inbox placement. Here is the one-minute pattern for adding seed addresses to every Mailchimp send.
Firebase / Supabase Auth Emails: Are Verification Emails Reaching Users?
If your signup verification email lands in spam, activation dies. Test Firebase and Supabase auth emails with real inbox placement, not just logs.
Stripe / Paddle Receipt Emails: Payment Confirmation Deliverability
Customers who do not get a receipt contact support. Stripe and Paddle send on your behalf — test real inbox placement for those emails here.
Typeform / Tally Response Emails: Deliverability Check
Form notifications from Typeform and Tally often go to Promotions or Spam. Test and fix deliverability before more submissions get lost.
Calendly Confirmation Emails: Do They Reach Your Clients?
A booking confirmation in spam is a missed meeting. Check Calendly confirmation deliverability across Gmail, Outlook, Yahoo and more.
ClickUp Email Notifications: Are They Hitting Spam?
Teams miss ClickUp mentions because notifications land in spam. Here is how to test, fix, and subscribe for the native ClickUp plugin beta.
Monday.com Email Notifications: Deliverability Test
Monday.com notifications are noisy and easily trained as Spam by users. Test placement and tune opt-in. Beta plugin waitlist open.
Airtable Email Deliverability: Do Your Automations Actually Reach People?
Airtable automations fire email on row changes. They look delivered in the log. Real inbox placement is a different story — test it here.
n8n Email Nodes: Free Inbox Placement Test for Self-Hosted Workflows
Self-host n8n and pair it with our free placement API. Every email your workflow sends can be placement-tested before scale.
Make.com (Integromat) Email Deliverability: Test Before Automating
Make.com chains modules to fire emails at scale. One misconfigured step sends everything to spam. Add a seed-test module before the Send.
Zapier Email Actions: How to Check Deliverability of Automated Emails
Zapier makes it trivial to automate email. It also makes it trivial to ship badly-configured email. Insert a deliverability check between zaps.
Freshsales / Freshdesk Email Deliverability: Test Your Support Emails
Support ticket replies going to spam breaks SLAs. Test Freshdesk outgoing placement before customers complain.
Pipedrive Email Deliverability: Are Your Sales Emails Reaching Prospects?
Pipedrive is a sales team favourite. Each rep's email reputation differs. Seed-test per sender and surface the weak ones fast.
HubSpot CRM Email Deliverability: Free Test Before Sequences
HubSpot CRM sequences send rep-level email at volume. A single misconfig kills reply rates across a team. Pre-test with seeds.
Salesforce Email Deliverability: Test Before Your Next Automation
Salesforce Marketing Cloud and sales Cadences operate at enterprise scale. The bigger the send, the bigger the cost of a placement miss.
Zoho CRM Email Deliverability: Why Leads Do Not Get Your Follow-Ups
Zoho CRM follow-ups land in Promotions more often than reps realise. Here is how to test before your next outreach cycle.
Microsoft 365 Email Deliverability: Test Before Sending Company-Wide
Microsoft 365 is tenant-scoped — a misconfigured connector hurts every user. Pre-deploy placement checks catch it before IT gets paged.
Google Workspace Email Deliverability: Test Your Business Emails
Workspace domains rarely land in Gmail spam — until they do. One bad DKIM push, every user affected. Seed-test company-wide sends first.
Framer Form Submissions: Email Deliverability Check
Framer sites rely on form notifications to drive leads. Submissions that do not reach the inbox are dead leads. Test placement from your Framer setup.
Notion Email Notifications: Do They Reach Your Team's Inbox?
Notion emails notifications for comments, mentions, calendar. When they land in spam, the team misses the ping. Test and subscribe for the plugin beta.
Webflow Form Email Deliverability: Why Submissions Go Missing
Webflow sites rely on form notifications to drive leads. Missing notifications = missing revenue. Check placement; join the Webflow plugin beta.
Ecwid / WooCommerce / Shopify: Order Email Deliverability Compared
A head-to-head of order-confirmation inbox placement across the three biggest e-commerce platforms. Data from our seed mailboxes.
Tilda Email Deliverability: Как проверить доставляемость форм (RU + EN)
Tilda-формы шлют письма с общих IP. Gmail отдаёт в Promotions, Mail.ru нередко в Spam. Пошаговая проверка + англоязычная версия.
Squarespace Email Deliverability: Test Your Form Notifications
Squarespace handles form emails through a shared sender. Placement is decent but not great for high-volume users. Seed-test your own site.
Wix Email Deliverability: Why Your Wix Forms Do Not Reach Inbox
Wix sends form notifications from wixemails.com — recipients often flag as spam. Test, diagnose, and join the Wix plugin beta.
BigCommerce Email Deliverability: Test Before Your Next Campaign
BigCommerce ships transactional and marketing email through mixed paths. A unified placement check catches both.
PrestaShop Email Deliverability: SMTP Setup and Inbox Test
PrestaShop uses PHP mail by default — which almost guarantees spam placement. Configure SMTP, then seed-test before enabling customer sends.
OpenCart Email Going to Spam: How to Test and Fix
OpenCart defaults send via PHP mail from the web host. SPF fails, DKIM missing, spam almost guaranteed. Fix list + seed test.
Magento / Adobe Commerce Email Deliverability: Transactional Email Guide
Magento transactional email fan-out is complex — order, shipment, invoice, credit memo. One misconfigured SMTP relay breaks all of them.
Shopify Email vs Third-Party ESP: Which Gets Better Inbox Placement?
Shopify Email is included in every plan. Mailchimp/Klaviyo cost money. The interesting question is which actually reaches inbox — we tested.
Shopify Email Deliverability: Why Order Confirmations Hit Spam
Shopify order-confirmation emails sometimes land in Gmail Promotions or Outlook Junk. Diagnose the cause and join the Shopify app beta.
1C-Bitrix Site Email Deliverability: Why Forms and Orders Go to Spam
1C-Bitrix defaults to PHP mail. Add SMTP + SPF/DKIM/DMARC, then seed-test. Guide in RU/EN plus beta waitlist for the Bitrix module.
Bitrix24 Email Deliverability: Test Your CRM Emails (CIS Market)
Bitrix24 is the CRM for much of the CIS. Its outbound email depends on the connector you pick. Seed-test per connector before enabling.
Typo3 Email Deliverability: Guide for German Market Websites
Typo3 is big in German enterprise. Transactional email via its Symfony Mailer integration still hits spam without proper DNS + IP setup.
Ghost Blog Email Deliverability: Are Your Newsletters Reaching Subscribers?
Ghost uses Mailgun under the hood for members. Placement varies wildly by domain. Seed-test every issue; join the Ghost plugin beta.
Drupal SMTP Module + Inbox Placement: Complete Guide
The Drupal SMTP module handles auth but not placement. Configure properly, then run a seed test. Full Drupal walkthrough.
Drupal Email Going to Spam: How to Diagnose and Fix
Drupal sites often send from PHP mail on the web host. That is almost guaranteed spam placement. Diagnose, fix, seed-test.
Joomla SMTP Configuration and Inbox Placement Test
Joomla needs SMTP + DMARC + a warm IP for any hope of inbox placement. Config walkthrough + seed-test at the end.
Joomla Email Deliverability: Why Your Site Emails Go to Spam
Joomla ships mail via PHP mail by default. SPF breaks, DKIM missing — spam nearly guaranteed. Diagnose, fix, join the Joomla extension beta.
WordPress + Mailchimp/Brevo: Test Deliverability of Your Newsletter Plugin
Newsletter plugins on WordPress route through Mailchimp or Brevo. The plugin hides the important knobs. Seed-test from outside to see the truth.
Contact Form 7 Emails Going to Spam: The Fix Nobody Talks About
CF7 triggers wp_mail which triggers PHP mail. That path produces spam. Install an SMTP plugin + seed-test. Full fix list.
Elementor Forms Email Deliverability: Why Submissions Disappear
Elementor forms rely on wp_mail. Without SMTP + DNS, submissions silently land in spam — or nowhere. Diagnose and fix with the free tester.
WordPress Multisite Email Deliverability: One Test for All Your Sites
Multisite networks often share a sending domain. A single placement issue affects every tenant. Centralised seed testing catches it once.
Gravity Forms + Inbox Check: Test Notifications Before They Go Live
Gravity Forms is the go-to premium forms plugin. Seed-test notifications before publishing; beta Gravity integration waitlist open.
WordPress Transactional Emails: Are Password Resets Hitting Spam?
WordPress password reset emails are the most important transactional email your site sends. They also go to spam most often. Test and fix.
WP Mail SMTP vs FluentSMTP vs Post SMTP: Which Actually Reaches Inbox?
The three leading WordPress SMTP plugins compared on real inbox placement — not just on "delivered to SMTP server".
How to Test If Your WordPress Emails Reach Inbox (Free, No Plugin)
You do not need to install a plugin to test placement. Use our free tester on top of any WordPress install. 2-minute walkthrough.
WordPress Email Deliverability Plugin: Test Inbox Placement From Dashboard (Beta)
Native WordPress plugin in private beta — run inbox placement tests from your wp-admin and alert on drops. Join the waitlist here.
WooCommerce Order Emails Going to Spam: How to Test and Fix
WooCommerce order emails hit spam surprisingly often — PHP mail, shared IPs, missing DNS. Full diagnosis + seed-test walkthrough.
Best WordPress SMTP Plugins 2026 — and Why They Do Not Check Inbox Placement
The top WordPress SMTP plugins reliably hand email to Mailgun/SendGrid/SES. None of them verify where the mail actually lands. Seed-test separately.
Postman Collection for Inbox Check API: Test Every Endpoint in 5 Minutes
Import one JSON file and hit every Inbox Check endpoint — auth, create test, poll, webhook verify, quota — without writing a line of code.
Slack Bot for Inbox Placement Alerts: Get Pinged When You Drop Below 80%
A 40-line Slack bot that watches your Inbox Check results stream and posts to a channel when inbox rate dips under a threshold. Full code included.
Grafana Dashboard for Inbox Placement Monitoring (JSON + API)
Scrape Inbox Check's API into a Grafana panel for per-provider inbox rate, DMARC alignment and DNSBL counts. The JSON dashboard to import.
Terraform Provider for Email Deliverability (Concept and Early Spec)
What a Terraform provider for Inbox Check would look like: resources for tests, schedules, webhooks, and why infra-as-code belongs around email too.
GitHub Actions: Test Email Deliverability on Every PR
Drop a single workflow file in .github/workflows. Every PR that touches your email templates or DNS now triggers a placement test and posts results.
Make.com (Integromat) + Inbox Check: No-Code Deliverability Monitoring
A no-code scenario that fires a placement test whenever a campaign is queued and posts the verdict to Airtable. Step-by-step walkthrough.
n8n + Inbox Check: Self-Hosted Email Deliverability Automation
Self-host n8n, wire it to Inbox Check, and run scheduled placement tests with Slack alerts — all without SaaS lock-in. Full workflow JSON.
Zapier Integration: Trigger Inbox Placement Tests From Any Workflow
Connect Inbox Check to Zapier: new Klaviyo campaign → placement test → Slack alert if spam rate > 20%. A 5-minute no-code setup.
Inbox Check Node.js SDK: npm install inbox-check (Full Reference)
The complete Node.js SDK reference — constructor options, tests.create, tests.get, tests.stream, webhooks, retry+timeout, TypeScript types.
Inbox Check Python SDK: pip install inbox-check (Full Reference)
Every method, every kwarg, every return type. The Python SDK reference — sync and async clients, pydantic response models, retry strategy.
Status Page and Incident History: Full Transparency on Uptime
Our public status page, the incidents we've had, how long we took to recover, and the postmortems behind each one.
Monitoring Our Own Deliverability: Eating Our Own Dog Food
Our transactional and marketing mail runs through Inbox Check every day. The dashboards we watch, the thresholds we alert on.
How We Process 1,000 Tests/Day on a Single Server (Architecture Post)
Postgres, BullMQ, Puppeteer, headless Gmail/Outlook sessions on one box. The architecture that keeps Inbox Check free and fast.
Seed Mailbox Rotation: How We Keep Test Results Accurate
Why seed mailboxes go stale, how we detect it, and the rotation process that keeps each provider's filter unbiased against test senders.
Infrastructure Behind Inbox Check: How We Maintain 20+ Seed Mailboxes
Real mailboxes on Gmail, Outlook, Yahoo, Mail.ru, Yandex, GMX, Orange, ProtonMail and more. The boring, expensive infrastructure few tools bother with.
Why We Do Not Gate the Free Tier Behind Email Verification
Every other deliverability tool asks for your email before you see your own DNS. We don't. Here is why — and the business math behind it.
Our Free Tier SLA: 99.9% Uptime, Sub-2-Minute Results, No Signup
A free tool does not have to mean a flaky tool. Here is our free-tier SLA, the infrastructure behind it, and where the paid tier adds real value.
The Future of Email Deliverability: AI Agents, MCP, and A2A
Where deliverability tooling is heading as AI agents become the primary consumer. MCP, A2A, and the end of the static dashboard.
AI Agents That Check Email Deliverability Autonomously (A2A + MCP Demo)
A working demo: an AI agent discovers our deliverability tools via A2A, runs a placement test through MCP, and diagnoses the failure on its own.
A2A Agent Discovery: .well-known/agent.json Explained
The .well-known/agent.json spec, how peer agents discover your capabilities, and the security considerations nobody covers yet.
How to Register Your Service as an A2A Agent (Step by Step)
Publish a valid Agent Card, expose a compliant endpoint, handle authentication — the full checklist to register with the A2A ecosystem.
Building a Multi-Agent Email QA Pipeline With A2A
A reviewer agent, a deliverability agent, a DNS agent — three agents coordinating over A2A to QA every email you send. Architecture + code.
A2A vs MCP: Which Protocol to Use for AI Agent Integrations
Both protocols matter — but for different things. MCP lets a model call your tools. A2A lets two agents talk. Here is when to use each.
A2A Agent Card for Email Testing: How Peer Agents Discover Our Tools
Our Agent Card at check.live-direct-marketing.online/.well-known/agent.json — the capabilities it advertises, the auth flow, example peer calls.
What Is A2A Protocol and How Email Deliverability Fits In
A2A (Agent-to-Agent) is Google's open protocol for agents to collaborate. Here is how a deliverability tool fits into an A2A pipeline — with examples.
npx ldm-inbox-check-mcp: Zero-Install Email Deliverability for AI Agents
One npx command, zero install, instant MCP server. The fastest way to give Claude or Cursor an email deliverability tool.
MCP Servers for Marketing: Email, SEO, Analytics — What Is Available in 2026
The current landscape of MCP servers for marketing workflows: deliverability, SEO audits, Google Analytics, Segment, HubSpot. An honest inventory.
How to Self-Host Our MCP Server (Docker + Environment Variables)
One Dockerfile, one env file, one bind mount. Run the Inbox Check MCP server on your own infrastructure with air-gapped API keys.
MCP vs REST API: When to Use Which for Email Deliverability
MCP is for interactive AI workflows. REST is for cron jobs and CI. Here is when each wins — and why most teams need both.
Building an AI Email Deliverability Agent With MCP and LangChain
A working LangChain agent that uses Inbox Check over MCP: runs placement tests, reads results, proposes DNS fixes, opens a PR. Full code.
Claude Code + MCP: Automate Email Infrastructure Checks From Terminal
Give Claude Code the Inbox Check MCP server. Now your terminal agent can audit DNS, run placement tests and fix records without switching windows.
Cursor + Inbox Check MCP: Test Deliverability Without Leaving Your IDE
Drop our MCP config into Cursor. Now Cursor's agent can test your transactional templates while you edit them. Setup in 2 minutes.
MCP Server for Email: 5 Tools Your AI Agent Can Call Right Now
start_test, get_test, check_auth, check_blacklist, list_providers. The five tools our MCP server exposes — with example LLM prompts for each.
How to Add Inbox Placement Testing to Claude Desktop in 2 Minutes
Paste one JSON block into claude_desktop_config.json, restart Claude, and ask it to test your sender. A 2-minute setup with screenshots.
What Is MCP and Why Your AI Agent Needs Email Deliverability Tools
Model Context Protocol (MCP) in plain English. Why giving your agent a deliverability tool changes what it can do for you.
Inbox Check API Error Handling: Retries, Timeouts, Idempotency
The error-handling contract: retriable vs terminal codes, recommended backoff, idempotency keys, and the one error class every integration gets wrong.
Inbox Check API Response Format: JSON Schema, Status Codes, Pagination
The response envelope, pagination semantics, cursor vs page, and the JSON schema you can paste into your OpenAPI generator.
Inbox Check API Free Tier: Rate Limits, Quotas, and Why It Is Generous
The real free-tier numbers: requests per minute, tests per day, concurrent streams. Plus the upgrade thresholds and why we don't gate SPF/DKIM checks.
How to Integrate Inbox Placement Tests Into Your SaaS Product
White-label deliverability checks inside your SaaS — how to wire up the API, display results, handle webhooks, and brand the output.
Inbox Check API: cURL Examples for Every Endpoint
Copy-paste cURL snippets for auth, create test, poll, stream, list, cancel, quota. The fastest way to kick the tires on our API.
Inbox Check API: Node.js SDK Quick Start (npm install inbox-check)
npm install, Bearer auth, first test, stream results, webhooks — the 10-minute Node.js quick start with TypeScript examples.
Inbox Check API: Python SDK Quick Start (pip install inbox-check)
pip install, auth, first test, async polling, streaming. The 10-minute Python quick start — sync + async flavours.
Monitoring Email Deliverability With Cron Jobs and Our API
A cron job, a 30-line Node script, and your inbox rate over time. The minimal monitoring stack for small teams.
How to Build an Email Deliverability Dashboard With Our API and React
A working React dashboard — inbox rate per provider, trend lines, DMARC alignment. Full code, SWR + Recharts + Inbox Check SDK.
Inbox Placement API vs GlockApps API: Free Tier, Limits and DX Compared
Request shape, auth, rate limits, SDK coverage, pricing. An honest side-by-side of the two APIs — for developers choosing where to integrate.
Webhook Integration: Get Notified When Your Inbox Placement Drops
Register a webhook, receive signed deliverability alerts, verify HMAC, route to Slack. Full payload format and a 40-line receiver example.
Inbox Check API: Authentication, Rate Limits, Error Handling
Bearer tokens, key rotation, rate-limit headers, 429 handling. The complete API contract you need to ship a reliable integration.
Automate Email Deliverability Checks Before Every Deployment
Block a bad email template from shipping: run a placement test in CI, fail the build on >20% spam, deploy confidently. A working recipe.
How to Run an Inbox Placement Test From Your CI/CD Pipeline
Put a deliverability test between "build" and "deploy". GitHub Actions, GitLab CI and CircleCI configs that work out of the box.
Inbox Placement Test API: Complete Developer Guide (REST, Auth, Endpoints)
The definitive developer guide — every endpoint, every parameter, auth flow, webhook lifecycle, SDK coverage. Bookmark this.
Automated Inbox Placement Testing With AI Agents: No GlockApps Needed
Schedule recurring placement tests from Claude, Cursor or a cron script. How to set up automated deliverability monitoring without a paid dashboard.
MCP Server for Email Deliverability: Test From Claude or Cursor (Free)
Drop our MCP server into Claude Desktop or Cursor, and let the agent run inbox placement tests, DMARC checks and DNSBL scans inline while you debug.
Inbox Placement Test API: Free Tier vs GlockApps ($59/mo and up)
Two REST calls and one SSE stream. The minimal API surface for an inbox placement test, benchmarked against GlockApps's paid-only API.
GlockApps Uptime Monitor Alternative: Do You Really Need It?
Sending-server uptime sounds useful until you read what it measures. A reality check on uptime monitoring and cheaper ways to get the same signal.
GlockApps DMARC Analyzer Alternative: Free Options That Actually Work
DMARC aggregate parsing you can do without a $59/mo dashboard. Five open-source and free tools, and which one to pick for your setup.
Email Header Analyzer: Parse SPF, DKIM and DMARC Results From Headers
How to read Received, Authentication-Results, ARC-* headers. Paste your raw header, get a plain-English verdict on every authentication check.
Rspamd Score Check: What Modern Spam Engines Think About Your Email
Rspamd is what Mailcow, Postfix and most modern MTAs actually run. The scoring symbols to watch, how to read them, and how to lower your score.
Email Authentication Test: SPF + DKIM + DMARC in One Click (Free)
Check all three records plus alignment in a single test. The one-page walkthrough of what "pass" actually means for each line.
DNSBL Check: Is Your IP on a Blacklist? Free Scan Across 50+ Lists
Spamhaus ZEN, SORBS, Barracuda, SURBL, URIBL — the DNSBLs worth checking and which to ignore. A free scan across 50+ lists in under 5 seconds.
Real Inbox Screenshots: See Exactly Where Your Email Lands (Free)
Not just "Inbox / Spam" — actual screenshots from Gmail, Outlook, Yahoo, Mail.ru and 20+ more. Why screenshot tests catch things verdict-only tools miss.
DNS Health Check for Email: MX, PTR, rDNS — All Free
One test that covers every DNS record your deliverability depends on: MX, SPF, DKIM, DMARC, PTR, FCrDNS, Spamhaus DBL. No signup.
Email Blacklist Check: Free Tool for IP and Domain (50+ Lists)
The blacklists that matter, the ones to ignore, and a free scanner that checks both your sending IP and your domain in a single run.
SpamAssassin Score: How to Check It Free Without GlockApps
SpamAssassin runs on millions of servers. How to get your real score, see which rules fired, and lower it — without paying for GlockApps.
Free SPF, DKIM and DMARC Check Online: No Signup
Paste your domain. Get SPF syntax, DKIM selector lookup, DMARC policy and alignment — instantly, without handing over an email address.
Free Inbox Placement Test: What GlockApps Charges $59/mo For
A straight answer to "do I need GlockApps?". What a placement test actually produces, and how to get the same output free with 20+ providers.
UniSender and SendPulse Deliverability: Free Test for CIS Senders
UniSender and SendPulse dominate the CIS market, but their own dashboards hide placement data. How to test Mail.ru and Yandex placement for free.
Klaviyo Email Deliverability: Free Test for E-commerce Senders
Klaviyo's "Delivered" rate is almost meaningless for Gmail Promotions. The pre-send routine that tells you whether your flow lands in Primary.
ConvertKit (Kit) Email Deliverability: Are Your Newsletters Hitting Inbox?
Kit's shared-IP reputation shifts constantly. How creators can run a placement test before every broadcast, and which setting fixes 60% of cases.
ActiveCampaign Deliverability: Free Inbox Placement Check
ActiveCampaign's "Delivery Rate" is not inbox placement. The quick test that shows you what their dashboard hides — plus the three settings to audit.
Brevo (Sendinblue) Deliverability Test: Free Alternative to GlockApps
Brevo sends from its own IPs — good for transactional, rough for marketing. The free pre-send test that catches shared-pool reputation hits.
HubSpot Emails Going to Spam: How to Diagnose and Fix
HubSpot-specific spam issues: shared tracking domain, "via hubspot.com", poorly warmed sending domains. The fix list for each.
Woodpecker Email Deliverability: Test Across 20+ Providers Free
Woodpecker's Inbox Ninja is bundled but limited. A free 20+ provider placement test you can run before every sequence launch.
Smartlead Deliverability: Free Inbox Test Before Your Campaign
Smartlead's unified inbox rotation is powerful — but it hides per-account placement. The pre-campaign check that tells you which inbox is burning.
Apollo.io Emails Going to Spam: How to Check and Fix (2026)
Apollo's shared sending pool moves in and out of Spamhaus SBL. How to test your real placement and the three settings that pull you back into Inbox.
Instantly Deliverability: What Their Dashboard Does Not Show You
Instantly shows warm-up progress and sends — but not per-provider placement. The three gaps in their dashboard and how to fill them for free.
Lemlist Deliverability Dropped? Free Inbox Placement Test to Find Out Why
If Lemlist suddenly lands in Spam across your sequence, it is almost always one of four causes. How to diagnose each in under 10 minutes.
Postmark vs SendGrid vs Amazon SES: Which Lands in Inbox? (We Tested)
We ran identical messages through Postmark, SendGrid and SES. Inbox rates, spam rates and what to expect on a shared pool vs dedicated IP.
Amazon SES Inbox Placement: Free Test Before You Scale
SES is cheap and powerful — until your shared pool gets a bad neighbour. How to run a free placement test before requesting your production limit.
SendGrid Deliverability Issues: How to Diagnose Before Paying for GlockApps
SendGrid's own reports stop at "Delivered". A free 10-minute diagnostic flow that tells you which shared pool you are on and where you actually land.
Mailchimp Emails Going to Spam? Test Your Placement Free Before Sending
Mailchimp's shared pool reputation shifts weekly. A free placement test to run before every campaign — before Mailchimp's own reports catch up.
Zoho Mail, Fastmail, HEY: Deliverability to Privacy-First Providers
Small audience, spiky filtering. How to get into Zoho, Fastmail and HEY inboxes — and what these three score differently from Gmail.
iCloud Mail Deliverability: Why Apple Users Do Not See Your Email
iCloud is 15% of US inboxes and almost no placement tool covers it. The three things iCloud punishes harder than Gmail — and the fix for each.
ProtonMail Deliverability: Does Your Email Even Get Through?
ProtonMail users are high-value and hard to reach. The ProtonMail-specific filtering quirks and how to validate placement before you send at scale.
WP.pl and Onet.pl: Email Deliverability for the Polish Market
Poland's two biggest ISPs have their own postmaster tools, their own blacklists, and their own quirks. A sender's guide nobody else publishes.
Orange, LaPoste, Free.fr: Email Deliverability for the French Market
Gmail tests are useless for a French B2C audience. How Orange, LaPoste and Free.fr filter mail — and what to verify before you ship a French campaign.
GMX and T-Online Email Deliverability: Guide for the German Market
Germany sits on GMX, Web.de and T-Online. Their filtering rules, their postmaster portals, and the authentication strictness nobody warns you about.
Cold Email to Russian Companies: Gmail vs Mail.ru vs Yandex Placement
Same message, three ISPs, wildly different results. The data behind cold-email placement in Russia and what it means for your sequence.
SPF and DKIM for Mail.ru: Step-by-Step Setup Guide
Mail.ru's postmaster is stricter than Gmail on DKIM selector length and SPF. The exact DNS records and a walkthrough of postmaster.mail.ru.
How to Test Inbox Placement for Russian Email Providers (Free)
Mail.ru, Yandex, Rambler, List.ru — four providers, four different filtering stacks. A single test that covers all of them for free.
Rambler Mail Deliverability: What Senders Need to Know
Rambler is tiny but stubborn: 4% of Russian inboxes and its own filter. The specifics of getting mail through Rambler's Spam folder.
Yandex Mail Spam Filter: How It Works and How to Avoid It
Yandex's spam filter is ML-heavy and domain-reputation-first. What postoffice.yandex.ru shows, what it hides, and the five things to fix first.
Mail.ru Email Deliverability: The Complete Guide for Senders
50M+ active Russian inboxes. Postmaster.mail.ru setup, FBL loop, DKIM strictness, SPF alignment — everything to know before you send to Mail.ru.
Yahoo Sender Hub vs Google Postmaster: Which Gives Better Insights?
Yahoo finally has a postmaster portal. How its signals, sampling and layout compare to Google's — and which one to check first.
Yahoo and AOL Mail Sender Requirements 2026: How to Pass Compliance
Yahoo aligned with Gmail on DMARC, one-click unsubscribe and <0.3% complaint rate. What the 2026 update changed and how to audit your compliance.
How to Test If Your Email Reaches Outlook Inbox (Free Tool)
Outlook, Hotmail, Live and Office 365 all use different SmartScreen signals. A single free test that covers every Microsoft-hosted mailbox type.
Microsoft 365 Email Deliverability: Why Outlook Treats You as Spam
M365 mailboxes are tenant-filtered on top of SmartScreen. The four M365-specific reasons your mail lands in Junk — and the fix for each.
Outlook / Hotmail Spam Filter: Why Your Emails Go to Junk and How to Fix It
SmartScreen runs on content signals Gmail ignores. The Outlook-specific triggers — and a 20-minute fix list that pulls most senders back to Inbox.
How to Test Email Deliverability to Gmail Without Paying for GlockApps
A free Gmail placement test that covers Inbox, Promotions, Updates, Social and Spam — across consumer and Workspace mailboxes.
Gmail Spam Filter in 2026: What Changed and How to Pass It
Gmail's 2026 updates tightened engagement weighting and DMARC enforcement. What shifted, how to detect if you are impacted, and what to change.
Gmail Inbox vs Promotions vs Spam: How to Test Where You Land (Free)
Three very different outcomes, same "delivered" status in your ESP. A free test that shows you the real Gmail tab — Primary, Promotions, Social or Spam.
Why Are My Emails Going to Spam? 12 Reasons and How to Fix Each One
From SPF misconfig to shouty subject lines — the twelve most common reasons your mail lands in Spam, with a concrete fix for each.
Best Free Email Deliverability Tools in 2026: Honest Comparison
Your ESP says "delivered" — but delivered where? A straight-shooting comparison of the 5 free tools that actually tell you whether your email reaches the Inbox, Spam, or Promotions.
Inbox Placement vs Delivery Rate: The Metric You're Ignoring
Your ESP's 99% delivery rate means nothing if 40% of it lands in Spam. Here's why inbox placement is the only number that matters.
Cold Email Deliverability: The Pre-Launch Checklist (2026)
The 17-point pre-flight checklist for cold outreach — DNS, warm-up, list hygiene, copy, sending cadence. Run before every campaign.
Gmail Spam Filter 2026: How It Works and How to Stay in Inbox
Gmail's filter uses ML on engagement, authentication, content and domain reputation. A practical breakdown of each signal and how to win at it.
What Is an Inbox Placement Test and Why You Need One Before Every Campaign
A smoke test for your email. What an inbox placement test actually does, how seed mailboxes work, and what you should do with the results.
Email Deliverability in 2026: The Complete Guide for Marketers
The only guide you need. Authentication, reputation, content, engagement — every deliverability lever explained in one place.
Emails Going to Spam in Outlook: 9 Fixes That Actually Work
Outlook's SmartScreen is stricter than Gmail. Nine concrete fixes for the most common reasons your mail ends up in Junk.
How to Warm Up a New Email Domain for Cold Outreach
A 4-week ramp plan for fresh domains: volume curves, engagement tactics, which warm-up services help, and which break you.
SPF Record: What It Is, How to Set It Up, and Common Mistakes
Everything about SPF in plain English. Syntax, includes, the 10-lookup limit, and the misconfigurations that silently kill deliverability.
DKIM Explained: How to Sign Your Emails and Why It Matters
What DKIM actually does, why Gmail demands it, how selectors work, and the two-line DNS record that gets you signing today.
Open Rate Is a Lie: Why Inbox Placement Is the Only Metric That Matters
Apple MPP, Outlook's blocked pixels, AI summaries. Why open rate has been broken since 2021 — and what to measure instead.
Why Your Cold Emails Land in Spam (and the 15-Minute Fix)
The three fixes that take you from 20% to 80% inbox: authentication, domain age signals, and removing the spam-trigger content patterns SDRs all copy.
We Tested 500 Domains: Here's Where Cold Emails Actually Land in 2026
Real data from 500 inbox-placement tests. Median inbox rate, the single biggest predictor of Spam placement, and provider-by-provider breakdown.
How to Check If Your IP Is Blacklisted (and How to Get Delisted)
Which blacklists matter, which to ignore, how to check all of them in one go, and the delisting process for Spamhaus, SORBS and Barracuda.
DMARC for Beginners: Set Up in 15 Minutes, Protect Your Domain Forever
No jargon. A 15-minute DMARC rollout from p=none to p=reject, the aggregate reports you should actually read, and the mistakes that lock out legitimate mail.
What Happens to Your Email After You Hit Send (Step by Step)
MX lookup, TLS handshake, RCPT TO, content scanning, filter routing. A guided tour of the journey from Send button to Inbox folder.
How to Check Email Deliverability Before Sending a Lemlist Campaign
Lemlist hands you the tools but not the verdict. A 5-minute pre-send routine that tells you whether your sequence will land in Inbox or Spam.
Email Warm-Up Tools Compared: Do They Actually Work in 2026?
Mailwarm, Warmup Inbox, Lemwarm, InboxReach, Warmy. What they actually do to your reputation — and which ones Gmail has started to catch.
Gmail vs Outlook vs Yahoo vs Mail.ru: Who Sends More to Spam? (20+ Providers Compared)
We ran identical messages through 20+ providers. The Spam rate ranking will change how you think about "deliverability".
Gmail Promotions Tab: Why You Land There and How to Get to Primary
The Promotions classifier isn't about being "promotional" — it's about a specific set of signals. Here are the eleven that matter.
Gmail and Yahoo 2024 Sender Requirements: What Changed and What to Do Now
DMARC mandatory, one-click unsubscribe, <0.3% spam complaint rate. A compliance walk-through for bulk senders still not aligned.
SPF, DKIM, DMARC: The Complete Authentication Checklist
One-page checklist covering every SPF/DKIM/DMARC record and alignment check you need to pass before sending a single campaign.
DMARC Alignment Failures: Why You Still Fail DMARC With SPF and DKIM Passing
The most misunderstood part of DMARC. Why your record says "pass" but the From domain doesn't align — and how to fix both SPF and DKIM alignment.
MX Records Explained: What They Are and How to Check Yours
MX priority, multiple MX records, MX vs A records, and the three misconfigurations that make your domain silently undeliverable.
How to Set Up DKIM for Google Workspace (Step-by-Step With Screenshots)
Admin Console → Apps → Gmail → Authenticate email. The whole setup in ten screenshots, plus the two common "DKIM is not active yet" gotchas.
Instantly.ai Deliverability: How to Monitor and Improve Inbox Placement
Instantly's built-in warm-up + rotation is a good start, but it isn't enough alone. The extra checks to run on each sending account every week.
How Many Cold Emails Can You Send Per Day Without Getting Banned?
Provider-by-provider sending limits, why 50/day is the new safe ceiling, and how to scale beyond with inbox rotation.
Email Bounce Types Explained: Hard vs Soft and What to Do About Each
5xx vs 4xx, reject vs defer, what Gmail's "our system has detected" really means, and the bounce rates that wreck your reputation.
Mail.ru, Yandex and Rambler Deliverability: The Only Guide for CIS Markets
If your audience is Russian-speaking, Gmail tests tell you almost nothing. How the three big CIS providers filter mail differently from Western ISPs.
Inbox Rotation for Cold Outreach: How to Set Up and Why It Matters
Multiple sending domains, sub-domain separation, round-robin inboxes. The right rotation setup to send 1000s of cold emails a day without burning reputation.
Sender Reputation Explained: How Gmail, Outlook and Yahoo Score You
What a reputation score actually is, what ISPs measure, and the five things a sender can control to push their score upwards in ~30 days.
PTR Record and Reverse DNS: Why Missing rDNS Kills Your Deliverability
Forward-confirmed reverse DNS, why Gmail silently rejects mail from IPs without a PTR, and how to set up rDNS on Hetzner, OVH, AWS and DigitalOcean.
European Email Providers: Deliverability Guide for GMX, Orange, LaPoste, Free.fr, T-online, WP.pl
Your Gmail test tells you nothing about Germany, France or Poland. How each major European ISP filters mail — and why one test covers them all.
Apollo.io Email Deliverability: Avoid Spam When Scaling Outreach
Apollo's shared-IP sending pool is a blessing and a curse. The Apollo-specific tweaks that keep you inboxing when other users torch the reputation.
Yahoo Spam Filter: How It Differs From Gmail and What Senders Must Know
Yahoo is still 8% of US B2C recipients. Its complaint loop, its IP-level reputation weighting, and the three things Yahoo punishes that Gmail doesn't.
How to Automate Inbox Placement Tests With AI Agents (MCP + Claude)
Give Claude Desktop or Cursor the Inbox Check MCP server and let the agent run tests, diagnose placement, and propose DNS fixes on its own.
How to Set Up DKIM and SPF for Microsoft 365
Defender → Email & collaboration → Policies & rules → Email authentication settings. Every click, plus the CNAME gotchas that trip up admins.
BIMI: How to Show Your Logo in Gmail and Yahoo Inbox
A full BIMI rollout — SVG Tiny PS, VMC, DMARC p=quarantine prerequisite — plus whether the $1,500 VMC is actually worth it for your brand.
SPF Too Many Lookups: How to Fix the 10-Lookup Limit
Why SPF flattening is half a solution, how to audit your lookup count, and the cleanest fix — dedicated subdomains per vendor.
Mailchimp Deliverability: Why Your Campaigns Land in Spam
Shared IPs, free-tier senders, "via mailchimp.com" in your headers. The Mailchimp-specific reputation problems and how to work around them.
Tracking Pixels in Cold Email: Do They Help or Hurt Deliverability?
The data behind image-trackers. Why a 1×1 gif correlates with 12% lower Gmail inboxing — and when it's still worth the hit.
HubSpot Email Deliverability: How to Test Before You Send
HubSpot's own "Sent" metric isn't inbox placement. A quick pre-send loop that adds real placement data to your HubSpot workflow.
ProtonMail, iCloud, Zoho, Fastmail: How Privacy-First Providers Filter Your Email
They're smaller but their users are harder to convert. How privacy-first ISPs rank your mail and the three things that get you into their inboxes.
Woodpecker vs Lemlist vs Instantly: Deliverability Compared
We ran the same 100-email campaign through all three. Inbox rates, warm-up behaviour, and where each tool silently hurts deliverability.
Google Postmaster Tools: How to Read Your Domain Reputation
The only honest window into how Gmail sees you. What each metric means, what "Medium" reputation actually costs you, and how to move each needle.
Custom Tracking Domain: Why You Need One and How to Set It Up
Default shared tracking domains are often blacklisted. How to set up a CNAME-based custom tracking domain in Lemlist, Instantly and HubSpot.
The Most Common SPF/DKIM/DMARC Errors (Based on 1,000 Tests)
We analysed 1,000 real deliverability tests. The seven authentication errors that show up over and over — and the exact record fix for each.
SpamAssassin Score: What It Means and How to Lower It
What each SpamAssassin rule is testing, why HTML/text ratio trips honest senders, and how to go from 8.1 to 0.9 without rewriting your template.
Building an Email Deliverability Monitor With Our API (Developer Guide)
A 30-minute walk-through: Bearer auth, scheduled tests, SSE result streaming, and a Slack alert when a sender's inbox rate drops below 80%.
Shared IP vs Dedicated IP for Email: Which Is Better?
When to pay for a dedicated IP, when shared-IP pools are actually better, and the volume threshold where the answer flips.
Inbox Placement Rates by Industry: Who Gets to Inbox and Who Doesn't
SaaS, e-commerce, crypto, recruiting, financial services. Median inbox rates per industry and why the bottom two industries get filtered harder.