According to Live Direct Marketing's daily Tranco top-1M scan (July 13, 2026), Mailgun is the email service provider (ESP) for 25,399 domains — 4.11% of 617,702 SPF-publishing domains. Detection method: include: mechanisms in the SPF record.
Mailgun is a cloud-based transactional email API service that allows developers and platforms to send, receive, and manage email programmatically. It provides SMTP relay, bounce handling, email validation, and DNS configuration for SPF, DKIM, and DMARC authentication.
Mailgun's footprint in the web's email infrastructure sits predominantly among smaller and mid-market websites rather than the largest brands, concentrated in the .com space. It frequently appears alongside Google Workspace, and the recent growth evident in SPF include data suggests that Mailgun is gaining share in the transactional email relay market.
| Tranco rank band | Domains | Share of its base |
|---|---|---|
| Top 1,000 | 30 | 0.1% |
| Top 10,000 | 271 | 1.1% |
| Top 100,000 | 2,822 | 11.1% |
| Top 1,000,000 | 19,448 | 76.6% |
| Unranked | 2,828 | 11.1% |
| TLD | Domains | Share | |
|---|---|---|---|
| .com | 13,673 | 53.8% | |
| .org | 1,381 | 5.4% | |
| .co.uk | 670 | 2.6% | |
| .net | 643 | 2.5% | |
| .nl | 526 | 2.1% | |
| .io | 526 | 2.1% | |
| .de | 486 | 1.9% | |
| .com.au | 375 | 1.5% | |
| .com.br | 294 | 1.2% | |
| .ru | 269 | 1.1% |
Cross-tabulated from the same daily snapshot — the other email services seen on the same 25,399 domains.
| Type | Service | Domains | Share of Mailgun users |
|---|---|---|---|
| Mailbox | Google Workspace | 9,606 | 37.8% |
| Mailbox | Microsoft 365 | 6,212 | 24.5% |
| Mailbox | Mailgun (inbound) | 2,096 | 8.3% |
| Mailbox | Self-Hosted | 1,577 | 6.2% |
| Mailbox | Unknown / Other | 913 | 3.6% |
| Mailbox | Mimecast | 539 | 2.1% |
| ESP | Amazon SES | 2,481 | 9.8% |
| ESP | Zendesk | 2,227 | 8.8% |
| ESP | SendGrid (Twilio) | 2,194 | 8.6% |
| ESP | Mailchimp | 2,158 | 8.5% |
Senders using Mailgun configure SPF includes that point to Mailgun's infrastructure, delegating outbound email authentication to Mailgun's managed service. Mailgun signs outbound mail with DKIM and handles bounce processing, but the domain's reputation depends on both its own sending practices and the shared reputation of Mailgun's broader sender base. Because Mailgun's user base spans smaller and mid-market websites, IP reputation is mixed, requiring individual senders to maintain strong authentication configuration, list hygiene, and engagement metrics to achieve consistent deliverability.
See the full Mailgun data page (KPI cards, trend, sample domains) →
Mailgun is a transactional email relay service that delegates a domain's outbound authentication to Mailgun's infrastructure. A domain's deliverability depends on correct SPF and DKIM configuration through Mailgun and its own sender reputation, not Mailgun's brand reputation.
25,399 domains in the Tranco top-1M use Mailgun as their email service provider (ESP) as of July 13, 2026 (4.11% of SPF-publishing domains), according to Live Direct Marketing's daily DNS scan.
Mailgun accounts for 4.11% 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.
Mailgun is growing — its share moved +0.04 pp over the last 30 days (as of July 13, 2026).
Mailgun's largest TLD is .com (53.8% of its domains); it appears across 418 TLDs in total.