POP3 Stops Responding

[msf004]

We have ran Network Edition 4.5.6 for over a year and recently we finally upgraded to 4.5.11 (yes - baby steps, we did not yet go to 5.x).

However, ever since the upgrade to 4.5.11 every 1-3 days the POP3 stops responding. Basically all of our customers using POP3 stop receiving email.

Through tests during these times I can tell you that IMAP still works, SMTP still works (everyone can send emails). However, just our customer using POP3 stop receiving emails.

The fix, so far, is to perform a zmcontrol stop/start which corrects the problem for a few days.

Does anyone have any ideas, where I should look for possible problems, etc.

Thank you for any assistance or information,
-Marc

[bdial]

when it stops working, is the server still listening on port 110 (pop3 port) or do you get connection refused o nthat port?

[msf004]

That is a good question. Next time it happens I will try to telnet to port 110 and see what happens.

I know that from the customers perspective, their email clients are telling them that the "POP Email Server is Not Respondind". However, that could be interpreted a few ways being that is just a message from Outlook.

Thanks,
-Marc

[msf004]

I have learned today that it is not only POP3 that stops responding, but also IMAP. This morning, again, everyone's email stopped working.

This seems to occur about every 48 hours. At least for the past 10 days, every other morning no one can connect to mail.

Again, the only change I made was to upgrade from 4.5.6 to 4.5.11. (I guess in the future if something is not broke don't fix it; at least I have heard that somewhere before).

Unfortunately, by the time I realized it had happened again this morning, I had 20 customers and 3 employees p!ssed - so I did not troubleshoot too much. I just did the zmcontrol stop/start and everything started working fine.

Again, when this happens SMTP still works - I can SEND out mail. Just no one can receive mail.

Does anyone have any ideas at what to look at? Should I just open a ticket w/ Zimbra? Suggestions?

Thanks,
-Marc