6.23%
AWS Simple Email Service — high-volume cloud email backbone for AWS workloads.
Email Service Providers (ESP) portfolio
← Back to landing · MX providers SaaS sendersCatalogue of Email Service Providers (ESPs) — marketing automation, transactional and customer-engagement platforms — authorised via SPF on Tranco top-1M domains. This is the dedicated mailing-services view; see SaaS senders for non-ESP business apps and MX providers for inbound mail.
185ESPs in current scan
185catalogued (with description)
46.97%of SPF-domains use any ESP
2026-09-24scan date · 637,420 SPF domains
Catalogue coverage progress (target 90%)
4.68%
Twilio SendGrid — transactional and marketing email API used by SaaS apps worldwide.
4.01%
Sinch Mailgun — developer-first transactional/relay email service.
3.61%
Intuit Mailchimp — newsletter and marketing automation, dominant SMB ESP in North America and EU.
3.26%
Mailchimp transactional add-on (formerly standalone).
3.18%
HubSpot CRM/Marketing Hub email — popular SMB inbound marketing platform.
2.57%
Salesforce CRM transactional/sales sends.
2.14%
France-origin transactional+marketing ESP, now Sinch group.
1.49%
French SMB ESP (rebranded from Sendinblue), strong in EU mid-market.
1.03%
Email marketing platform using mlsend.com for SPF authentication.
0.70%
Canadian low-cost email API and marketing platform.
0.61%
Unisender — Russian email and SMS marketing platform, one of the most popular ESPs in the RU/CIS market.
0.58%
US small-business newsletter platform.
0.56%
Australia-origin newsletter ESP (Marigold), popular with agencies.
0.50%
Zoho Campaigns marketing automation (zcsend.net).
0.50%
Adobe Marketo Engage — B2B marketing automation, enterprise-grade.
0.47%
Transactional email service known for high deliverability and developer UX.
0.46%
Generic transactional/marketing infra (emsd1.com).
0.46%
Ukrainian/UA-origin multi-channel marketing platform.
0.43%
MessageBird-owned high-volume transactional email backbone.
0.41%
Zoho transactional email API (transmail.net / zoho-mail.com).
0.35%
US helpdesk SaaS sending customer-support emails.
Salesforce ExactTarget — enterprise marketing automation suite.
0.30%
Transactional email API by MailerLite team.
0.26%
Brazilian leading marketing automation (RD Station, by Resultados Digitais).
No historical data yet.
0.25%
Long-running US SMTP relay service for marketers.
No historical data yet.
0.23%
Italian marketing automation, enterprise B2C.
0.20%
New Zealand transactional email service.
0.17%
Ukrainian multi-channel marketing automation (Promodo group).
No historical data yet.
0.16%
Krakow-based marketing automation (Benhauer).
No historical data yet.
0.15%
Italian SMTP relay service.
No historical data yet.
0.15%
US deliverability + ESP infrastructure.
No historical data yet.
0.15%
UK SMTP relay for SMB outbound.
0.14%
Polish transactional email platform (Vercom group).
No historical data yet.
0.14%
Polish marketing email platform.
No historical data yet.
0.13%
Freshworks Freshmarketer — marketing automation.
No historical data yet.
0.13%
Generic sender service (sendersrv.com).
No historical data yet.
0.13%
ZeptoMail — Zoho transactional email API.
No historical data yet.
0.12%
Low-cost transactional SMTP relay.
No historical data yet.
0.12%
Zoho Mail 360 — multi-tenant business email API.
No historical data yet.
0.12%
Dutch transactional email platform, B2B-leaning.
No historical data yet.
0.12%
Repica WebCAS — Japanese email marketing platform.
No historical data yet.
0.11%
UniSender — CIS email marketing platform.
No historical data yet.
0.11%
BizMatrix Vail — Japanese marketing email platform.
No historical data yet.
0.11%
US SMB+mid-market newsletter platform (CM Group).
No historical data yet.
0.11%
Russian email marketing platform (DashaMail).
No historical data yet.
0.11%
Newsletter2Go — German SMB ESP, now part of Brevo.
No historical data yet.
0.11%
Sendsay — Russian email marketing platform with surveys + automation.
No historical data yet.
0.10%
Polish-origin email marketing, widely used in EU SMB.
No historical data yet.
0.10%
Mindbox — Russian CDP + email/SMS/push marketing automation.
No historical data yet.
0.10%
Marigold Sailthru — publisher-focused personalisation ESP.
0.09%
E-commerce-focused marketing automation, dominant on Shopify.
No historical data yet.
0.09%
Netcore Cloud — customer engagement and email API.
No historical data yet.
0.09%
Customer messaging platform — transactional + lifecycle email.
No historical data yet.
0.08%
Argentinian/Latin-America marketing automation.
No historical data yet.
0.08%
HDEMS — outsourced email marketing operations.
No historical data yet.
0.08%
Zoho Campaigns India residency.
No historical data yet.
0.08%
Cuenote (Toban) — Japanese email marketing platform.
No historical data yet.
0.08%
Mailtrap — email testing & sending API.
No historical data yet.
0.07%
Enterprise on-premise/hybrid email engine.
No historical data yet.
0.07%
Lifecycle marketing automation for product teams.
0.07%
Act-On — mid-market marketing automation platform.
No historical data yet.
0.07%
US Democratic-party fundraising/CRM platform.
No historical data yet.
0.07%
SmartEmailing — Czech SMB email marketing platform.
No historical data yet.
0.06%
Adestra MessageFocus — UK enterprise email platform (now Upland).
No historical data yet.
0.06%
APSIS — Swedish ESP, strong Nordic SMB presence.
No historical data yet.
0.06%
NewsMAN — Romanian email marketing service.
No historical data yet.
0.06%
Q-Send — Japanese email delivery service.
No historical data yet.
0.06%
Visual marketing-automation builder (now Ortto).
No historical data yet.
0.06%
iCoreMail — Indian email marketing platform.
No historical data yet.
0.06%
Doppler — LATAM email marketing, strong in Argentina.
No historical data yet.
0.06%
Stibee — Korean newsletter platform.
No historical data yet.
0.05%
CrmStyle — Italian email marketing platform.
No historical data yet.
0.05%
CRM + email marketing for very-small businesses.
No historical data yet.
0.05%
Liana Technologies — Finnish marketing automation suite.
No historical data yet.
0.05%
Polyglot small-business newsletter platform.
No historical data yet.
Net-Results marketing automation (emailcampaigns.net).
No historical data yet.
Blackbaud Luminate Online — nonprofit fundraising + email.
No historical data yet.
0.05%
French ecommerce abandoned-cart automation.
No historical data yet.
0.05%
UniOne (UniSender) — Russian transactional email API.
No historical data yet.
0.05%
French transactional ESP, part of Sinch / Mailjet group.
No historical data yet.
0.05%
Alibaba Cloud DirectMail (DM) transactional/marketing email (CN+APAC).
No historical data yet.
0.05%
MailGaner — Russian email marketing platform.
No historical data yet.
0.05%
Sendergen — bulk email service, India-based.
No historical data yet.
0.05%
Veteran small-business newsletter platform.
No historical data yet.
0.05%
Chilean marketing automation, LatAm reach.
No historical data yet.
0.05%
Vienna-origin enterprise marketing platform, now SAP CX.
0.04%
Greek omnichannel marketing automation (Athens).
No historical data yet.
0.04%
CARMA — niche US ESP (carmamail.com SPF infra).
No historical data yet.
0.04%
Spanish SMB email marketing platform.
No historical data yet.
0.04%
Oracle Eloqua — enterprise B2B marketing automation.
No historical data yet.
0.04%
Engaging Networks — nonprofit advocacy email.
No historical data yet.
0.04%
US promotions/loyalty platform with email engine (secondstreetmail.com).
No historical data yet.
0.04%
WiLL Mail — Japanese email delivery service.
No historical data yet.
0.04%
Israeli email marketing automation, popular in MENA/EU.
No historical data yet.
0.04%
Flexmail — Belgian email marketing.
No historical data yet.
0.04%
edrone — Polish e-commerce CRM/email.
No historical data yet.
0.04%
MailPlus — Dutch email marketing service.
No historical data yet.
0.04%
Dutch affiliate-marketing SaaS sending tracked notifications.
No historical data yet.
0.04%
Scaleway Transactional Email Manager (FR cloud).
No historical data yet.
0.04%
All-In Mail — Brazilian email marketing platform.
No historical data yet.
0.03%
Salsa Labs — nonprofit advocacy + email engagement.
No historical data yet.
0.03%
Adestra MessageProvider — UK enterprise email infrastructure.
No historical data yet.
0.03%
CyberMail — Japanese email marketing system.
No historical data yet.
0.03%
Estonian newsletter ESP (Tallinn).
No historical data yet.
0.03%
Mailkit — Czech enterprise email marketing.
No historical data yet.
0.03%
Spotler — UK marketing automation platform.
No historical data yet.
0.03%
Maropost — Canadian marketing cloud, B2C focus.
No historical data yet.
0.03%
InterNetX (Munich) SMTP relay used by registrar customers.
No historical data yet.
0.03%
Tricorn — Chinese marketing automation/email platform.
No historical data yet.
0.03%
artegic emailsys — Bonn-based enterprise CRM/email platform.
No historical data yet.
Alibaba DirectMail Singapore region.
No historical data yet.
0.03%
Webempresa hosting outbound mail.
0.03%
Indian transactional+marketing email API (sendclean.net).
No historical data yet.
0.03%
German B2B marketing-automation by SC-Networks (Evalanche, scnem.com).
No historical data yet.
0.03%
Transactional Mail (Japan) — JP transactional email API.
No historical data yet.
0.03%
Neon One — nonprofit CRM email.
No historical data yet.
0.03%
Selzy — email marketing platform (formerly Estismail).
No historical data yet.
0.03%
Your Mailing List Provider — Belgian newsletter ESP.
No historical data yet.
0.03%
Polish newsletter and automation ESP (Krakow).
No historical data yet.
0.03%
Newsweaver NE16 — secondary sending domain.
No historical data yet.
0.02%
Higher Logic Informz — association email marketing.
No historical data yet.
Message Business — French email marketing platform.
No historical data yet.
0.02%
Pinpointe — B2B email marketing platform.
No historical data yet.
0.02%
Rule — Swedish marketing automation.
No historical data yet.
0.02%
QuickPivot — multichannel marketing automation.
No historical data yet.
0.02%
ReSender — Russian email distribution platform.
No historical data yet.
0.02%
BeSender — Japanese email marketing service.
No historical data yet.
0.02%
India-origin marketing automation, strong in APAC.
No historical data yet.
0.02%
emSMTP — transactional/marketing relay.
No historical data yet.
0.02%
Synergy! Marketing — Japanese marketing cloud.
No historical data yet.
0.02%
MTARGET — Indonesian email/SMS marketing.
No historical data yet.
0.02%
JangoMail / Email Galaxy — high-volume bulk email.
No historical data yet.
0.02%
Treasure Ship — Japanese email marketing service.
No historical data yet.
0.02%
Akna — Brazilian email marketing platform.
No historical data yet.
0.02%
ESP1 — Korean email service provider.
No historical data yet.
0.02%
Australian transactional email API and SMTP relay.
No historical data yet.
0.02%
Masiv — Colombian SMS/email marketing.
No historical data yet.
0.02%
Paloma — Swedish email marketing platform.
No historical data yet.
0.02%
EBlastEngine — bulk email service.
No historical data yet.
0.02%
SendCloud (Sohu) — Chinese transactional email.
No historical data yet.
0.02%
Copernica — Dutch email marketing software.
No historical data yet.
0.02%
Inforu — Israeli SMS/email marketing.
No historical data yet.
0.02%
Contactlab — Italian customer engagement platform.
No historical data yet.
0.02%
Dito — Brazilian CDP and email marketing.
No historical data yet.
0.02%
Send-Box — Russian email marketing platform.
No historical data yet.
0.02%
SNDR — Norwegian email distribution.
No historical data yet.
0.02%
Fidelizador — Chilean email marketing platform.
No historical data yet.
0.02%
Perfit — Argentinian email marketing.
No historical data yet.
0.02%
Bullhorn — recruitment CRM with built-in email.
No historical data yet.
0.02%
Lifecycle and transactional email platform.
No historical data yet.
0.02%
Indonesian email-marketing and automation platform.
No historical data yet.
0.02%
Newsweaver — Irish enterprise newsletter ESP.
No historical data yet.
0.02%
French newsletter and campaign-mailing platform.
No historical data yet.
0.02%
Mailigen — Latvian SMB ESP, acquired by Pipedrive.
No historical data yet.
0.01%
French customer-marketing and loyalty automation platform.
No historical data yet.
0.01%
Canadian email-marketing platform focused on SMB and compliance.
No historical data yet.
0.01%
Reply.io — Ukrainian sales engagement and cold-email automation.
No historical data yet.
0.01%
Italian email-marketing and automation platform.
No historical data yet.
0.01%
Useinbox — Turkish SMB email marketing platform.
No historical data yet.
0.01%
E-commerce email and SMS marketing automation.
No historical data yet.
0.01%
Q4 — investor-relations communications and IR press distribution.
No historical data yet.
0.01%
Newsletter and RSS-to-email delivery platform.
No historical data yet.
Constant Contact — US SMB newsletter ESP, decades-old leader.
No historical data yet.
0.01%
Resulticks Falconide — APAC marketing automation.
No historical data yet.
0.01%
Pepipost — transactional email API by Netcore Cloud.
No historical data yet.
0.01%
Turkey-origin omnichannel marketing and email platform.
No historical data yet.
0.01%
Data Driven Email — analytics-led email service.
No historical data yet.
0.01%
Theeml — RU-CENTER email marketing platform.
No historical data yet.
0.01%
Ontraport — SMB CRM + marketing automation.
No historical data yet.
0.01%
Get-N-Post — Russian newsletter service.
No historical data yet.
0.01%
Creator-focused newsletter platform (rebranded to Kit).
No historical data yet.
0.01%
Zoho Campaigns EU residency.
No historical data yet.
0.00%
Estonia-origin sales CRM.
No historical data yet.
0.00%
SiteSell Solo Build It! — affiliate marketing newsletter platform.
No historical data yet.
Omnisend
0.00%
Lithuanian e-commerce marketing automation.
No historical data yet.
Braze
0.00%
Customer engagement platform popular with consumer apps.
No historical data yet.
Beehiiv
0.00%
Newsletter platform popular with creators and media.
No historical data yet.
MailPoet
0.00%
WordPress-native newsletter plugin (Automattic-owned).
No historical data yet.
Dotdigital
0.00%
UK marketing automation, enterprise B2C.
No historical data yet.
Flodesk
0.00%
Design-first newsletter for creators and small biz.
No historical data yet.
ActiveCampaign
0.00%
CRM + marketing automation for SMBs.
No historical data yet.
Mailtrap (testing)
0.00%
Email-testing sandbox + transactional sending.
No historical data yet.
0.00%
Zoho generic campaign SPF.
No historical data yet.
Iterable
0.00%
Cross-channel growth marketing platform (mid-market).
No historical data yet.
No ESPs match the filter.
Maintain this catalogue programmatically
The same SPF classifier that builds /providers.html and /saas.html powers this page. To submit a batch of unknown SPF includes for tier 1-3 classification (heuristic → RDAP → web), POST to:
POST https://<analyzer-host>:8090/classify
Content-Type: application/json
{"hosts": ["spf.example.com", "_spf.foo.io", "..."]}
→ returns batch_id; poll /batch/<id> for results + dict diff.
Confidence-≥0.8 RDAP/web matches are auto-promoted into PURE_ESP / GATEWAYS / FORWARDERS. Lower-confidence matches land in a shadow queue for human review before merging.
Source: OpenINTEL forward-DNS Tranco snapshot (2026-09-24).
ESP patterns: dictionaries/esps.py.
Descriptions: dictionaries/saas_meta.py.
Sparklines render only for senders tracked in history.json; new
ESPs will start appearing as future scans accumulate.