IMAP clients unable to connect

[morrisjones]

Running:
Release 8.8.15.GA.3869.UBUNTU18.64 UBUNTU18_64 FOSS edition, Patch 8.8.15_P45.

Over the past month I've been finding that IMAP clients (Thunderbird, apple mail) have occasionally been unable to connect, or hang forever trying to log in.

If I do a zmcontrol restart, it clears up the issue.

(a) Can you suggest a troubleshooting path? I'm not sure where to start
(b) Is there a single service I can restart instead of the whole stack? I'm not sure which one clients connect to.

(The answer to which service will help me diagnose the hanging problem.)

The clients are connecting on port 993.

Mojo
--
Morris Jones
Monrovia, CA

[ghen]

(a) Can you suggest a troubleshooting path? I'm not sure where to start

Look at /opt/zimbra/log/mailbox.log when this happens.

(b) Is there a single service I can restart instead of the whole stack? I'm not sure which one clients connect to.

You can restart just mailboxd with "zmmailboxdctl restart quick" (as zimbra user).
This leaves mysql, ldap, nginx, postfix, etc alone.

[liverpoolfcfan]

How many clients? Are you running out of connections?

Code: Select all

[zimbra@mail ~]$ zmprov gcf zimbraImapMaxConnections
zimbraImapMaxConnections: 200

If you suspect you are you could bump up this number