Transactional Email APIs · reliability comparison
Postmark vs SMTP2GO: which is more reliable? (2026)
Postmark is more reliable than SMTP2GO, scoring 68.3 vs 58.4 out of 100. Over the last 90 days Postmark reported 8 incidents and SMTP2GO reported 17, with effective uptime of 99.58% and 99.17% respectively. SMTP2GO resolves incidents faster on average (5h 39m).
Data updated Nov 1, 2026 · How we score
| Metric | Postmark | SMTP2GO |
|---|---|---|
| Reliability score | 68.3 | 58.4 |
| Rank (transactional email APIs) | #9 | #11 |
| Uptime (90 days) | 99.58% | 99.17% |
| Incidents (90 days) | 8 | 17 |
| Partial / major outages | 0 | 3 |
| Avg time to resolve | 7h 41m | 5h 39m |
| Outages we detected | 0 | 0 |
| Transparency score | 100/100 | 100/100 |
Where Postmark and SMTP2GO differ
- SMTP2GO reported 2.1× as many incidents as Postmark over the last 90 days (17 vs 8).
- SMTP2GO had 3 partial or major outages, compared with 0 for Postmark.
- SMTP2GO fixes problems faster: 5h 39m on average, against 7h 41m for Postmark.
- Postmark's longest outage on record lasted 1d 3h (Feb 1, 2026); SMTP2GO's lasted 1d 4h (Jan 22, 2026).
90-day uptime
Postmark
SMTP2GO
- No incidents
- Degraded
- Partial outage
- Major outage
- No data
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
Recent SMTP2GO incidents
- Degraded performanceOct 30, 2026 · resolved in 10h 12m
Affected: API Servers
- Partial outageOct 15, 2026 · resolved in 2h 20m
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 →