Mailtrap email service provider (ESP)
According to Live Direct Marketing's daily Tranco top-1M scan (September 24, 2026), Mailtrap is the email service provider (ESP) for 494 domains — 0.08% of 637,420 SPF-publishing domains. Detection method: include: mechanisms in the SPF record.
Key facts
- 494 domains in the Tranco top-1M use Mailtrap (0.08% of SPF-publishing domains).
- Snapshot date: 2026-09-24 — recomputed every day.
- Strongest TLD: .com (43.9% of its domains).
- Most co-used service: Google Workspace.
- Directory category: email service provider.
Why Mailtrap appears in this category
Mailtrap — email testing & sending API.
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.
Mailtrap is a transactional email platform developed by Railsware that provides hosted SMTP infrastructure for application-generated mail. It serves organisations that need reliable outbound email delivery without operating their own mail servers, offering both a sandbox testing environment for development and production relay services.
Mailtrap's footprint across SPF records shows it occupies the infrastructure layer for smaller and mid-market organisations rather than enterprise-scale deployments. Its frequent co-occurrence with Google Workspace indicates a common pattern where organisations use Google for primary email but route application notifications through Mailtrap's managed infrastructure, and its global distribution reflects adoption across diverse geographies and business verticals.
Where Mailtrap sits in the Tranco ranking
| Tranco rank band | Domains | Share of its base |
|---|---|---|
| Top 1,000 | 0 | 0.0% |
| Top 10,000 | 2 | 0.4% |
| Top 100,000 | 56 | 11.3% |
| Top 1,000,000 | 432 | 87.4% |
| Unranked | 4 | 0.8% |
Top-level domain split
| TLD | Domains | Share | |
|---|---|---|---|
| .com | 217 | 43.9% | |
| .org | 19 | 3.8% | |
| .com.br | 18 | 3.6% | |
| .net | 15 | 3.0% | |
| .io | 13 | 2.6% | |
| .nl | 10 | 2.0% | |
| .fr | 9 | 1.8% | |
| .id | 8 | 1.6% | |
| .ch | 8 | 1.6% | |
| .ng | 8 | 1.6% |
What Mailtrap users also use
Cross-tabulated from the same daily snapshot — the other email services seen on the same 494 domains.
| Type | Service | Domains | Share of Mailtrap users |
|---|---|---|---|
| Mailbox | Google Workspace | 169 | 34.2% |
| Mailbox | Microsoft 365 | 95 | 19.2% |
| Mailbox | Self-Hosted | 56 | 11.3% |
| Mailbox | Unknown / Other | 23 | 4.7% |
| Mailbox | Zoho Mail | 16 | 3.2% |
| Mailbox | Generic / unmatched (mx*.*) | 11 | 2.2% |
| ESP | Amazon SES | 54 | 10.9% |
| ESP | Zendesk | 33 | 6.7% |
| ESP | Mailgun | 30 | 6.1% |
| ESP | HubSpot | 27 | 5.5% |
SPF alignment and shared IP reputation
Organisations using Mailtrap as a mail relay must include Mailtrap's SMTP infrastructure in their domain's SPF record to pass authentication checks. Because Mailtrap operates shared IP addresses used by many customers simultaneously, sender reputation is influenced by the collective sending behaviour of all users on that IP block; poor list hygiene or spam complaints from other customers can result in shared-IP blacklisting that affects all senders using that IP.
See the full Mailtrap data page (KPI cards, trend, sample domains) →
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Frequently asked questions
Should I test email deliverability with Mailtrap?
Mailtrap can validate SMTP delivery and message formatting, but as a mail relay it does not simulate delivery to consumer mailboxes like Gmail or Outlook. For production deliverability testing, integrate with real mailbox providers or dedicated testing services.
How many domains use Mailtrap?
494 domains in the Tranco top-1M use Mailtrap as their email service provider (ESP) as of September 24, 2026 (0.08% of SPF-publishing domains), according to Live Direct Marketing's daily DNS scan.
Is Mailtrap common enough to affect email deliverability testing?
Mailtrap accounts for 0.08% 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 Mailtrap most?
Mailtrap's largest TLD is .com (43.9% of its domains); it appears across 100 TLDs in total.