Transactional Email APIs · reliability comparison

SMTP2GO vs SparkPost (Bird): which is more reliable? (2026)

SparkPost (Bird) is more reliable than SMTP2GO, scoring 87.7 vs 58.4 out of 100. Over the last 90 days SMTP2GO reported 17 incidents and SparkPost (Bird) reported 8, with effective uptime of 99.17% and 99.90% respectively. SparkPost (Bird) resolves incidents faster on average (2h).

Data updated Nov 1, 2026 · How we score

SMTP2GO

58.4/100

Operational

Visit SMTP2GO ↗

SparkPost (Bird)

87.7/100

Operational

Visit SparkPost (Bird) ↗

Metric	SMTP2GO	SparkPost (Bird)
Reliability score	58.4	87.7
Rank (transactional email APIs)	#11	#5
Uptime (90 days)	99.17%	99.90%
Incidents (90 days)	17	8
Partial / major outages	3	0
Avg time to resolve	5h 39m	2h
Outages we detected	0	0
Transparency score	100/100	100/100

Where SMTP2GO and SparkPost (Bird) differ

SMTP2GO reported 2.1× as many incidents as SparkPost (Bird) over the last 90 days (17 vs 8).
SMTP2GO had 3 partial or major outages, compared with 0 for SparkPost (Bird).
SparkPost (Bird) fixes problems faster: 2h on average, against 5h 39m for SMTP2GO (2.8× quicker).
SMTP2GO's longest outage on record lasted 1d 4h (Jan 22, 2026); SparkPost (Bird)'s lasted 7h 30m (Jul 24, 2026).

90-day uptime

SMTP2GO

90 days ago99.169% average daily uptimeToday

SparkPost (Bird)

90 days ago99.903% average daily uptimeToday

No incidents
Degraded
Partial outage
Major outage
No data

Recent SMTP2GO incidents

Degraded performanceOct 30, 2026 · resolved in 10h 12m
API Error
Affected: API Servers
Partial outageOct 15, 2026 · resolved in 2h 20m
Softbounce Errors
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
Connectivity Issues
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)

Full SMTP2GO reliability report →

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
Mail delivery delays
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

Full SparkPost (Bird) reliability report →

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 →