Is Lettermint down?

Status: Investigating We are investigating failing requests and retries affecting SMTP relay. Affected components Click tracking (Degraded performance) Open tracking (Degraded performance) Sending API (Degraded performance) Team API (Degraded performance) Incoming (Degraded performance) SMTP Relay (Degraded performance)

Status: Resolved On September 1, between 04:01 and 04:06 UTC, one of our API instances returned errors for a small number of requests. Some customers sending email through our API or SMTP service might have seen a submission or authentication error. Other instances remained healthy, and most requests continued normally. No email already accepted by Lettermint was lost. Failed requests stopped before we accepted or created the message, so clients could retry them after service recovery. A small number of email-open events might not have been recorded. No stored customer data was changed or exposed. The cause was a defect in the PHP JIT. We already had a safeguard for this issue, but it did not cover this additional code path. We expanded the safeguard and removed the affected date calculation from the application startup process. This lets us keep the performance optimisation active for the rest of the application. We will also install the permanent PHP fix when it becomes available in our production runtime which at the time of writing is not the case. We continue to monitor the service. We are sorry for the disruption. Affected components Team API (Operational) Incoming (Operational) SMTP Relay (Operational) Click tracking (Operational) Open tracking (Operational) Sending API (Operational)

Status: Investigating We have been made aware of this issue reoccurring again and are currently investigating. The incident has already been mitigated by killing the affected pod. We will share an update once we know more. Affected components Click tracking (Degraded performance) Open tracking (Degraded performance) Sending API (Degraded performance) Team API (Degraded performance) Incoming (Degraded performance) SMTP Relay (Degraded performance)

Status: Resolved This incident has been resolved. SMTP relay and API are operating normally again. We have deployed further mitigation measures to prevent this incident from occurring again and are keeping a close eye. Apologies for the inconvenience this has caused. Affected components Sending API (Operational) Team API (Operational) Incoming (Operational) SMTP Relay (Operational) Click tracking (Operational) Open tracking (Operational)

Status: Investigating We’ve identified that one of our outbound broadcast IP addresses have been blocklisted, affecting email delivery for some customers. The team is currently investigating the cause and working on delisting the IP. In the meantime, the IP address has been suspended and will not be used until the issue is resolved. This does not affect other IPs in the pool nor transactional routes. If you have seen a hard bounce because of this, you can safely reactivate the recipient from your suppression management. Affected components Outgoing (Broadcast) (Degraded performance)

Status: Identified We have identified the source of the listing and are actively remediating the issue. We will keep monitoring the situation. Our sincere apologies for the inconvenience. Affected components Outgoing (Broadcast) (Degraded performance)

Status: Resolved We have fully removed the affected IP address from active sending and traffic has been rerouted across our remaining broadcast infrastructure. Email delivery is operating normally again. The affected IP will remain out of service while we continue working with Microsoft on the block. As this no longer impacts active sending, we are marking this incident as resolved. Transactional routes and other broadcast IPs remain unaffected. Affected components Outgoing (Broadcast) (Operational)

Status: Monitoring We are seeing elevated timeouts when accessing object storage due to an ongoing cloud provider outage. Our failover systems are operating as expected, but some requests may still time out. We are monitoring the situation closely. Affected components Team API (Degraded performance)

Status: Resolved The cloud provider outage has been resolved, and inbound emails and attachments can now be retrieved normally. We have not observed any further timeouts. Affected components Team API (Operational)

Status: Investigating We are investigating an increase in 503 Service Unavailable responses. Affected components Lettermint website (Operational) SMTP Relay (Partial outage) Outgoing (Broadcast) (Operational) Lettermint UI (Operational) Sending API (Partial outage) Team API (Partial outage) Outgoing (Transactional) (Operational) Incoming (Partial outage) Webhooks (Operational)

Status: Monitoring We experienced a brief period of API unavailability, during which some requests returned 503 Service Unavailable. Multiple API instances temporarily became unresponsive at the same time, leaving insufficient capacity to serve requests. Service has been restored and remains stable. We are monitoring closely and investigating what caused the instances to become unresponsive. Affected components Lettermint website (Operational) Team API (Operational) Outgoing (Transactional) (Operational) Incoming (Operational) SMTP Relay (Operational) Outgoing (Broadcast) (Operational) Webhooks (Operational) Lettermint UI (Operational) Sending API (Operational)

Status: Resolved API availability has been fully restored and the platform has remained stable. We reverted a health-check configuration that reacted too aggressively to a brief traffic spike, causing healthy instances to be temporarily removed from service. We have confirmed normal operation and are reviewing additional safeguards to prevent a recurrence. Affected components Lettermint UI (Operational) Team API (Operational) Outgoing (Transactional) (Operational) Incoming (Operational) Outgoing (Broadcast) (Operational) Lettermint website (Operational) Sending API (Operational) SMTP Relay (Operational) Webhooks (Operational)

Status: Investigating We are seeing increased error rates on the Lettermint dashboard and our Team API. Requests to the Team API and actions in the dashboard may fail or respond slowly while we look into this. Email delivery is not affected. Transactional and broadcast messages are still being sent and processed as normal. Our team is investigating the cause and we will post an update shortly. Affected components Lettermint UI (Degraded performance) Team API (Degraded performance)

Status: Monitoring We are no longer seeing elevated error rates on the Team API or dashboard and functionality appears to have returned to normal. We are continuing to monitor the situation closely to ensure stability, but no new errors have been observed since mitigation was applied. Affected components Lettermint UI (Operational) Team API (Operational)

Status: Resolved This incident has been resolved. We applied a fix and have confirmed that the dashboard and Team API are working normally, with no further errors. Affected components Lettermint UI (Operational) Team API (Operational)