MailerSend Outage History

28 incidents recorded over the last 365 days, 28 of them resolved. Durations are measured from when PulsAPI first saw the problem to when it cleared, which is usually longer than the vendor's own figure.

Live MailerSend status100.00% uptime history

Every Recorded MailerSend Incident

MailerSend incidents, newest first, with date, duration and status.
DateIncidentDurationStatus
Oct 11, 2026Database maintenanceMaintenance has started32 minResolved
Sep 15, 2026Scheduled maintenance - Email sending affected, 5 minMaintenance has started137h 41mResolved
Aug 17, 2026Scheduled maintenance - Email sending affected, 30 minWe are scheduling a maintenance window of 30 minutes on the 25th of August, 2026 at 7 am UTC. This maintenance will stop all email sendings (single email endpoint, bulk endpoint, SMTP). All emails sent during this…23h 42mResolved
Feb 19, 2026Technical issuesWe experienced a technical issue in the MailerSend app that may have caused problems for some users. The issue has been fixed. We apologize for any inconvenience.-2229330 minResolved
Feb 19, 2026We are experiencing a technical issueThe incident was resolved, no emails have been lost during the process.-1833304 minResolved
Feb 19, 2026The issue has been resolvedUsers have faced a lot of 500 server errors from 2:46 am UTC on the morning of 10th Oct, 22. SRE has been paged at 4:31 am UTC and noticed it was a storage issue. The storage caused errors while creating new files in…-1856945 minResolved
Feb 19, 2026We are experiencing a technical issueThe technical issue has been resolved. The App is back to normal. Thank you so much for your patience.-1955795 minResolved
Feb 19, 2026We're experiencing a technical issueThis incident has been resolved.-1744748 minResolved
Feb 19, 2026APP and API downtimeWe had an unexpected downtime due to a data migration. It has been resolved, apologies for any inconvenience caused.-1716695 minResolved
Feb 19, 2026We're experiencing a technical issueThis incident has been resolved.-1744414 minResolved
Feb 19, 2026We're experiencing a technical issueThis incident has been resolved.-1744924 minResolved
Feb 19, 2026We are experiencing a technical issueThe technical issue has been resolved. The App is back to normal. Thank you so much for your patience.-1714023 minResolved
Feb 19, 2026Email activity dataWe are sorry to inform you that all existing email activity data has been lost. All new data is in place, and email activity functionality works now. Please do contact our support if you need assistance.-1602875 minResolved
Feb 19, 2026Backend server problemsWe had a downtime on one of our backend database servers. The problem has been fixed.-1624595 minResolved
Feb 19, 2026Degraded performanceThis incident has been resolved.-1686358 minResolved
Feb 19, 2026We experienced a technical issueThis incident has been resolved.-1503283 minResolved
Feb 19, 2026We're experiencing a technical issue resulting in a 401 error increaseThe incident was solved. You should no longer receive 401 errors when calling the API.-1221484 minResolved
Feb 19, 2026Technical issue on our SMTP proxySome of our users experienced a service interruption today between 4:30 and 5:10pm (GMT+2) when connecting to our SMTP proxy. After investigation, we found out the certificate on our SMTP proxy caused some clients…-1294625 minResolved
Feb 19, 2026We've experience a technical issue on our bulk endpointWe experienced a technical issue that caused delays while using the bulk endpoint. The bulk-sending feature was down between 12:50 UTC and 15:12 UTC on April 10th and between 11:24 UTC and 12:16 UTC on April 11th. We…-980105 minResolved
Feb 19, 2026Delayed delivery timeThe slowdown was absorbed.-1039926 minResolved
Feb 19, 2026Email delivery and activity status problemsToday, we encountered technical challenges that led to delays in email delivery and discrepancies in activity reporting. Specifically, between 08:00 UTC and 12:00 UTC, some users may have experienced delays in sending…-960935 minResolved
Feb 19, 2026We are experiencing a technical issueWe experienced slowdowns in sendings, on our single and bulk email endpoints. This affected a few accounts for around 2 hours. Our team investigated the issue and found that our sending servers had a memory leak. After…-971847 minResolved
Feb 19, 2026We are experiencing a technical issueDeliverability rate should be back to normal.-839609 minResolved
Feb 19, 2026We are experiencing a technical issueThe problem should be resolved now, sorry for the inconvenience.-900255 minResolved
Feb 19, 2026Mail transfer agent delivery report delayWe have recently encountered technical difficulties that have affected the accuracy of email activity reporting within our platform. Between May 18 05:15 UTC to May 19 16:05 UTC, some users may have experienced delayed…-923135 minResolved
Feb 19, 2026We are experiencing a technical issueThis incident has been resolved.-637943 minResolved
Feb 19, 2026Delays in webhook deliveries on 2-DEC-2024We want to acknowledge and apologize for an issue that caused delays in webhook deliveries. The issue began at approximately 2024-12-02 16:30 UTC and was resolved at 2024-12-02 22:00 UTC. The system is now fully…-640145 minResolved
Feb 19, 2026We're experiencing a technical issue - delays on webhooks and bulk email sendingOur team successfully identified and patched the underlying problem, and the incident has been resolved. Thank you for your patience, The MailerSend team-767449 minResolved

Hear about the next one while it is open

Everything above is a record written after the fact. We can email you when the next MailerSend incident opens instead, at the point where knowing still changes what you do.

Free, no password, no card. Unsubscribe in one click.

How to Read This MailerSend Incident Log

Each row is an incident PulsAPI observed, not a summary written afterwards. The duration is wall-clock time between the first failing check and the first clean one, so it includes the window before MailerSend acknowledged anything. Vendor post-mortems typically measure from acknowledgement, which is why their numbers are usually shorter.

Incidents still open have no duration yet and are listed as ongoing rather than being given a running total. The archive covers the last 365 days; anything older has aged out of the window rather than never having happened.

The longest single MailerSend outage in this window ran 5d 17h, against a mean recovery of 2d 5h. If you depend on MailerSend in a customer-facing path, the longest figure is the one to design around. The mean is what happens on a normal bad day; the maximum is what happens on the worst one.