Incident report: IMAP client service temporarily unstable..

Last night at 21:50 UTC a large number of client connections hit Kolab Now, which resulted in the IMAP client servers (‘imap.kolabnow.com’) running out of memory. Staff was noted about the issue at 06:00 UTC, and immediately raised the amount of memory for these servers, which brought the issue to an end.

During these ~8 hours users of IMAP clients had issues with unstable connections; some might even have been completely unable to connect.

Mail transport was not impacted. all mails were streaming in and out as they should, and also the webclient (‘https://kolabnow.com/apps’) worked well during the period.

The issue was the unusually large number of incoming client connections. To mitigate the situation and avoid similar issues, the staff has enlarged the memory size on the servers in question, and are now working to improve the monitoring of the service.

We regret the incident and apologize for any inconvenience that this may have caused.