Some users are experiencing long delays in sending emails

[robp2175]

Some users emails are taking 30 or sometimes more seconds to send an email. Yesterday, I believed I had fixed this when it appeared one of our domain controllers (Active Directory) was locking up and I removed it from the list of servers that Zimbra authenticates against. However, today I am getting reports that sending emails is slow again. I might need some help regarding where to look and what logs to check in order to provide more information. Any assistance would be greatly appreciated. I am on version
Release 8.8.15.GA.3869.UBUNTU18.64 UBUNTU18_64 FOSS edition, Patch 8.8.15_P9.

[L. Mark Stone]

Some users emails are taking 30 or sometimes more seconds to send an email. Yesterday, I believed I had fixed this when it appeared one of our domain controllers (Active Directory) was locking up and I removed it from the list of servers that Zimbra authenticates against. However, today I am getting reports that sending emails is slow again. I might need some help regarding where to look and what logs to check in order to provide more information. Any assistance would be greatly appreciated. I am on version
Release 8.8.15.GA.3869.UBUNTU18.64 UBUNTU18_64 FOSS edition, Patch 8.8.15_P9.

Finding out where the bottleneck is is the key challenge.

You can run "top" and see if you are CPU bound, RAM bound (if the system is swapping) or I/O bound (if the %wa is above single digits).

As the Zimbra user, you can run "qshape" from a commandline to look at the ageing of your mai queues.

From the Admin Console, you can look at your mail queues and see if any backscatter or other spurious emails are clogging things up -- and then delete those emails right from the Admin Console.

Unfortunately, sometimes when people report Zimbra is all of a sudden "slow", it's because an account has been compromised and is sending large amounts of spam email.

Hope that ehlps,
Mark