Another quick fix post!


A mailbox was not receiving mail on a postfix & dovecot on a Plesk server. The following error messages were being shown in the mail log:

$ tail -f /var/log/maillog
Apr 25 15:04:34 server01 dovecot: service=imap, [email protected],
ip=[]. Error:
modseq_hdr.log_offset too large

As you can see the the error is: “modseq_hdr.log_offset too large”.

I’m not sure what caused this (I think it’s related to the dovecot.index file – but not 100% sure), but this quick solution fixed it.


To fix this, delete all dovecot files (config and index files) from the users mail directory:

$ find /var/qmail/mailnames/ -name "dovecot*" -delete

Restart Postfix & Dovecot (to rebuild the dovecot files):

$ service dovecot restart
$ service postfix restart

Warning: This fix removes the dovecot configuration and index files for that specific user. Make sure you back them up before running the above command!

By magic the mailbox began to receive email!