Transactional Email APIs · reliability comparison
Mailgun vs SparkPost (Bird): which is more reliable? (2026)
SparkPost (Bird) is more reliable than Mailgun, scoring 87.7 vs 83.2 out of 100. Over the last 90 days Mailgun reported 10 incidents and SparkPost (Bird) reported 8, with effective uptime of 99.84% and 99.90% respectively. Mailgun resolves incidents faster on average (1h 43m).
Data updated Nov 1, 2026 · How we score
| Metric | Mailgun | SparkPost (Bird) |
|---|---|---|
| Reliability score | 83.2 | 87.7 |
| Rank (transactional email APIs) | #7 | #6 |
| Uptime (90 days) | 99.84% | 99.90% |
| Incidents (90 days) | 10 | 8 |
| Partial / major outages | 3 | 0 |
| Avg time to resolve | 1h 43m | 2h |
| Outages we detected | 0 | 0 |
| Transparency score | 100/100 | 100/100 |
Where Mailgun and SparkPost (Bird) differ
- Mailgun reported 25% more incidents than SparkPost (Bird) over the last 90 days (10 vs 8).
- Mailgun had 3 partial or major outages, compared with 0 for SparkPost (Bird).
- Mailgun fixes problems faster: 1h 43m on average, against 2h for SparkPost (Bird).
- Mailgun's longest outage on record lasted 3h 37m (May 25, 2026); SparkPost (Bird)'s lasted 7h 30m (Jul 24, 2026).
90-day uptime
Mailgun
SparkPost (Bird)
- 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 SparkPost (Bird) incidents
- InformationalOct 30, 2026 · resolved in 22h 2m
Outbound message delivery is delayed/slow for some SparkPost customers (US hosted only)
Affected: SMTP Delivery - USA
- Degraded performanceOct 28, 2026 · resolved in 1h 1m
Outbound message delivery is delayed/slow for some SparkPost customers (US hosted only)
Affected: SMTP Delivery - USA
- Degraded performanceOct 11, 2026 · resolved in 3h 6m
Increased message delays in US and EU due to DNS resolution errors
Affected: SMTP Delivery - USA, SMTP Delivery - EUROPE
- Degraded performanceOct 1, 2026 · resolved in 31m
Affected: SMTP Delivery - USA, SMTP Delivery - EUROPE
- Degraded performanceSep 17, 2026 · resolved in 54m
Outbound message delivery is delayed/slow for some SparkPost customers (US hosted only)
Affected: SMTP Delivery - USA
- Degraded performanceSep 14, 2026 · resolved in 2h 27m
Health Score and Cohort data is delayed
Affected: SparkPost Application - USA, SparkPost Application - EUROPE
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 →