Resend Outage History

Resend experienced a 51-minute outage where new customers were unable to create custom tracking domains due to an upstream infrastructure limit. Existing tracking domains and email sending functionality remained unaffected throughout the incident. The issue was resolved by working with the infrastructure provider, and failed provisioning requests from the outage window were being replayed.

Resend experienced a 47-minute incident where email event statuses were delayed and incorrectly displayed as "Queued," though actual email sending and delivery continued to function normally. The team identified the root cause and deployed a fix, after which webhook deliveries and email event statuses caught up and resumed real-time updates.

Resend experienced a 3-hour delay in updating email event statuses, causing emails to incorrectly display as "Queued" even though they were being sent and delivered normally. The team identified and deployed a fix, allowing all queued events to catch up and resume real-time status updates.

Resend experienced increased latency in email event updates for 2.9 hours. The service identified the cause of queued events and worked through the backlog to resolve the issue. Email event processing was delayed but the system continued operating with reduced performance.

Resend experienced increased latency affecting broadcast email sending and domain verification processes for 2.8 hours. The issue was traced to a third-party provider, who implemented improvements to resolve the performance problems. Both broadcast email throughput and domain verification times returned to normal after the provider's fixes were deployed.

Resend experienced a major service incident where users encountered 404 errors when attempting to send emails through both the SMTP service and API. The issue affected email sending functionality for 1.4 hours before engineers identified the root cause and applied fixes to restore service. The incident was resolved after monitoring confirmed the fixes were successful across all affected systems.

Resend experienced increased latency in email sending that affected customers using both SMTP service and API, causing delays in email delivery. The issue was identified as affecting a subset of customers and was actively investigated by the team. The problem was resolved after 59 minutes, with all emails returning to normal delivery speeds.

Resend experienced increased latency in email event updates for 11 minutes on March 26, 2026. The service classified this as a minor incident affecting the timeliness of email event processing. The issue was under investigation during the outage period.

Resend experienced errors preventing contacts from successfully unsubscribing from audiences and segments. The unsubscribe functionality was affected, blocking users from opting out of email communications. The incident lasted 1.2 hours and was resolved.

Resend experienced delayed Email Events following scheduled maintenance, lasting 1.4 hours. The service confirmed that while events were processed with delays, no data was lost during the incident. The issue was identified and resolved without permanent impact to email functionality.