MailerSend email service provider (ESP)

According to Live Direct Marketing's daily Tranco top-1M scan (July 13, 2026), MailerSend is the email service provider (ESP) for 7,924 domains — 1.28% of 617,702 SPF-publishing domains. Detection method: include: mechanisms in the SPF record.

Key facts

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 bandDomainsShare of its base
Top 1,00010.0%
Top 10,000520.7%
Top 100,0007068.9%
Top 1,000,0006,10677.1%
Unranked1,05913.4%

Top-level domain split

TLDDomainsShare
.com3,48344.0%
.pl5126.5%
.org3674.6%
.net1962.5%
.lt1722.2%
.io1642.1%
.co.uk1602.0%
.nl1411.8%
.com.br1221.5%
.hu1151.5%

What MailerSend users also use

Cross-tabulated from the same daily snapshot — the other email services seen on the same 7,924 domains.

TypeServiceDomainsShare of MailerSend users
MailboxGoogle Workspace3,02438.2%
MailboxMicrosoft 3651,50319.0%
MailboxSelf-Hosted1,21915.4%
MailboxUnknown / Other4625.8%
MailboxZoho Mail1291.6%
MailboxGeneric / unmatched (mx*.*)1281.6%
ESPAmazon SES7028.9%
ESPMailgun5466.9%
ESPMailchimp5366.8%
ESPSendGrid (Twilio)4525.7%

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) →

Are your emails landing in spam?
Run a free inbox-placement test across Gmail, Outlook, Yahoo and more — see exactly where your mail lands and why.
Test inbox placement →

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?

7,924 domains in the Tranco top-1M use MailerSend as their email service provider (ESP) as of July 13, 2026 (1.28% 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 1.28% 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.

Is MailerSend growing or declining?

MailerSend is growing — its share moved +0.03 pp over the last 30 days (as of July 13, 2026).

Which countries or TLDs use MailerSend most?

MailerSend's largest TLD is .com (44.0% of its domains); it appears across 263 TLDs in total.

Other email service provider (ESP)s

Amazon SES (6.21%)SendGrid (Twilio) (4.76%)Mailgun (4.11%)Zendesk (3.86%)Mailchimp (3.69%)Mandrill (3.36%)HubSpot (3.18%)Salesforce (2.62%)Mailjet (Sinch) (2.13%)Cloudflare Email Routing (1.80%)