What exactly means "deinit".

Yesterday I had all IMAP processes with word "deinit" in brackets and dovecot reached the limit of processes.
I had to do a restart of the process.

eg.:

dovecot   32482  0.0  0.0  24832  4256 ?        S    03:29   0:00 dovecot_host1/imap [pierrot xxx.xxx.xx.xx (deinit)]

Dovecot version 2.2.32.

Regards,
Jack