Transactional Email APIs · reliability comparison
Mailgun vs SMTP2GO: which is more reliable? (2026)
Mailgun is more reliable than SMTP2GO, scoring 83.2 vs 58.4 out of 100. Over the last 90 days Mailgun reported 10 incidents and SMTP2GO reported 17, with effective uptime of 99.84% and 99.17% respectively. Mailgun resolves incidents faster on average (1h 43m).
Data updated Nov 1, 2026 · How we score
| Metric | Mailgun | SMTP2GO |
|---|---|---|
| Reliability score | 83.2 | 58.4 |
| Rank (transactional email APIs) | #6 | #11 |
| Uptime (90 days) | 99.84% | 99.17% |
| Incidents (90 days) | 10 | 17 |
| Partial / major outages | 3 | 3 |
| Avg time to resolve | 1h 43m | 5h 39m |
| Outages we detected | 0 | 0 |
| Transparency score | 100/100 | 100/100 |
Where Mailgun and SMTP2GO differ
- SMTP2GO reported 70% more incidents than Mailgun over the last 90 days (17 vs 10).
- Mailgun fixes problems faster: 1h 43m on average, against 5h 39m for SMTP2GO (3.3× quicker).
- Mailgun's longest outage on record lasted 3h 37m (May 25, 2026); SMTP2GO's lasted 1d 4h (Jan 22, 2026).
90-day uptime
Mailgun
SMTP2GO
- 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 SMTP2GO incidents
- Degraded performanceOct 30, 2026 · resolved in 10h 12m
Affected: API Servers
- Partial outageOct 15, 2026 · resolved in 2h 20m
Softbounce Errorsofficial update ↗
Affected: Email sending (SMTP service)
- InformationalOct 8, 2026 · resolved in 1h 26m
Issues with API- statusCode=500
Affected: API Servers
- Degraded performanceOct 1, 2026 · resolved in 8h 26m
Affected: Email sending (SMTP service)
- InformationalOct 1, 2026 · resolved in 33m
Connection issues and 'processed' emails
Affected: Email sending (SMTP service)
- InformationalSep 30, 2026 · resolved in 8m
Issues connecting to mail.smtp2go.com
Affected: Email sending (SMTP service)
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 →