I spent most of this afternoon struggling with a mail issue and I didn’t find it documented well anywhere else, so I’m going to write about it here in the hopes that it might help someone else.
What I was trying to do: Setup qmail + vpopmail + courier imap for imap and pop3d
Problem I was having: For some users, checking POP3 mail would work for a while (about 5 minutes), but then would fail:
Jul 5 00:30:34 vkurup pop3d: LOGIN FAILED, ip=[::ffff:220.127.116.11] Jul 5 00:30:34 vkurup pop3d: Disconnected, ip=[::ffff:18.104.22.168]
The failure would only happen for users who had vpopmail accounts and shell accounts. Users who have only vpopmail accounts were fine.
Eventually, after much searching, I found this message which advised to configure courier-imap with
--without-authdaemon. This solved my problem.
According to the author of courier-imap, this problem is solved in newer versions of vpopmail, but he mentions version 5.3.38 and I could only find version 5.3.20, so I didn’t try that fix.