MailerSend email service provider (ESP)
According to Live Direct Marketing's daily Tranco top-1M scan (September 12, 2026), MailerSend is the email service provider (ESP) for 1,944 domains — 0.31% of 629,828 SPF-publishing domains. Detection method: include: mechanisms in the SPF record.
Key facts
- 1,944 domains in the Tranco top-1M use MailerSend (0.31% of SPF-publishing domains).
- Snapshot date: 2026-09-12 — recomputed every day.
- Strongest TLD: .com (41.2% of its domains).
- Most co-used service: Google Workspace.
- Directory category: email service provider.
Why MailerSend appears in this category
Transactional email API by MailerLite team.
We classify it as a email service provider from include: mechanisms in the SPF record matching a maintained provider rule. This is infrastructure attribution from public DNS, not evidence of a direct contract or exclusive use.
MailerSend is an email service provider that handles outbound mail delivery for websites and applications. It is identified in email infrastructure through SPF (Sender Policy Framework) include mechanisms, which indicate when a sender has delegated their mail delivery to MailerSend's authorised sending servers.
MailerSend's footprint is concentrated amongst smaller websites and brands rather than the largest enterprises, with deployments spread internationally across many top-level domains and concentrated in .com registrations. It is frequently observed alongside Google Workspace, and its recent growth in adoption means email professionals increasingly encounter MailerSend-authenticated mail and should account for it when assessing sender infrastructure and configuring email filters and deliverability tests.
Where MailerSend sits in the Tranco ranking
| Tranco rank band | Domains | Share of its base |
|---|---|---|
| Top 1,000 | 0 | 0.0% |
| Top 10,000 | 9 | 0.5% |
| Top 100,000 | 169 | 8.7% |
| Top 1,000,000 | 1,754 | 90.2% |
| Unranked | 12 | 0.6% |
Top-level domain split
| TLD | Domains | Share | |
|---|---|---|---|
| .com | 801 | 41.2% | |
| .org | 89 | 4.6% | |
| .com.br | 75 | 3.9% | |
| .net | 66 | 3.4% | |
| .co.uk | 51 | 2.6% | |
| .nl | 49 | 2.5% | |
| .de | 45 | 2.3% | |
| .io | 36 | 1.9% | |
| .pl | 32 | 1.6% | |
| .it | 30 | 1.5% |
What MailerSend users also use
Cross-tabulated from the same daily snapshot — the other email services seen on the same 1,944 domains.
| Type | Service | Domains | Share of MailerSend users |
|---|---|---|---|
| Mailbox | Google Workspace | 697 | 35.9% |
| Mailbox | Microsoft 365 | 400 | 20.6% |
| Mailbox | Self-Hosted | 253 | 13.0% |
| Mailbox | Unknown / Other | 74 | 3.8% |
| Mailbox | Cloudflare Email Routing | 43 | 2.2% |
| Mailbox | Zoho Mail | 41 | 2.1% |
| ESP | MailerLite | 322 | 16.6% |
| ESP | Amazon SES | 158 | 8.1% |
| ESP | Mailgun | 150 | 7.7% |
| ESP | Mailjet (Sinch) | 110 | 5.7% |
SPF authorisation and delegated sending infrastructure
MailerSend operates as a delegated sending authority: domain owners explicitly authorise its IP ranges in their SPF records via include mechanisms. This delegation is cryptographically verifiable to receiving mail servers during SPF validation. For filtering, security, and deliverability teams, the presence of MailerSend's SPF include is a definitive signal of outsourced mail delivery infrastructure and clarifies that the domain owner has intentionally delegated sending to MailerSend rather than operating their own mail servers.
See the full MailerSend data page (KPI cards, trend, sample domains) →
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Frequently asked questions
Should I test email deliverability against MailerSend-authenticated senders?
Yes. Given its growing adoption amongst smaller website owners, MailerSend-authenticated traffic represents increasingly common real-world scenarios for inbox placement testing. You can identify such senders by examining their SPF records for MailerSend's include mechanism.
How many domains use MailerSend?
1,944 domains in the Tranco top-1M use MailerSend as their email service provider (ESP) as of September 12, 2026 (0.31% of SPF-publishing domains), according to Live Direct Marketing's daily DNS scan.
Is MailerSend common enough to affect email deliverability testing?
MailerSend accounts for 0.31% of SPF-publishing domains in the top 1M. Whether you should seed a test mailbox there depends on how much of your audience it represents — the co-usage table above shows the services it appears alongside most.
Which countries or TLDs use MailerSend most?
MailerSend's largest TLD is .com (41.2% of its domains); it appears across 174 TLDs in total.