"Re-Authentication Failure" when pop mailbox is locked

[fulax]

Hello,

One of our mail customer is frequently impacted by this error, and after searching around, I found the Loop Detection section of the man page that mention the exact error message, but in a totally different situation that ours.

I found out that our pop server reports an error "mailbox is locked" when perdition tries to proxy the pop session. The POP3 server response during login is:

-ERR [IN-USE] mailbox already in use by pid 12345

Could the error message returned to the client be improved in such situations?

Thanks.