Transactional Email APIs · reliability comparison
Mailgun vs Postmark: which is more reliable? (2026)
Mailgun is more reliable than Postmark, scoring 83.2 vs 68.3 out of 100. Over the last 90 days Mailgun reported 10 incidents and Postmark reported 8, with effective uptime of 99.84% and 99.58% respectively. Mailgun resolves incidents faster on average (1h 43m).
Data updated Nov 1, 2026 · How we score
| Metric | Mailgun | Postmark |
|---|---|---|
| Reliability score | 83.2 | 68.3 |
| Rank (transactional email APIs) | #7 | #10 |
| Uptime (90 days) | 99.84% | 99.58% |
| Incidents (90 days) | 10 | 8 |
| Partial / major outages | 3 | 0 |
| Avg time to resolve | 1h 43m | 7h 41m |
| Outages we detected | 0 | 0 |
| Transparency score | 100/100 | 100/100 |
Where Mailgun and Postmark differ
- Mailgun reported 25% more incidents than Postmark over the last 90 days (10 vs 8).
- Mailgun had 3 partial or major outages, compared with 0 for Postmark.
- Mailgun fixes problems faster: 1h 43m on average, against 7h 41m for Postmark (4.5× quicker).
- Mailgun's longest outage on record lasted 3h 37m (May 25, 2026); Postmark's lasted 1d 3h (Feb 1, 2026).
90-day uptime
Mailgun
Postmark
- No incidents
- Degraded
- Partial outage
- Major outage
- No data
Recent Mailgun incidents
- Degraded performanceOct 28, 2026 · resolved in 1h 4m
Affected: Inbound email processing
- Degraded performanceSep 30, 2026 · resolved in 42m
Affected: Inbound email processing
- Degraded performanceSep 14, 2026 · resolved in 58m
Affected: Inbound email processing
- Major outageSep 4, 2026 · resolved in 17m
Affected: API, SMTP, Outbound Delivery, Inbound email processing, Events & Logs, Stats and Analytics
- InformationalSep 4, 2026 · resolved in 34m
- Degraded performanceAug 31, 2026 · resolved in 7h 14m
Affected: Events & Logs
Recent Postmark incidents
- Degraded performanceOct 27, 2026 · resolved in 1h 43m
- MaintenanceOct 7, 2026 · resolved in 3h
- Degraded performanceSep 28, 2026 · resolved in 2h 6m
- Degraded performanceSep 28, 2026 · resolved in 3h 59m
- Degraded performanceSep 22, 2026 · resolved in 20m
- Degraded performanceSep 17, 2026 · resolved in 1h 33m
Other transactional email APIs to consider
- Mailjet · #1 · 100% uptime
- Mailtrap Email Sending · #2 · 99.99% uptime
- Loops · #3 · 99.98% uptime
- Twilio SendGrid · #4 · 99.98% uptime
See the full most reliable transactional email apis ranking →