After upgrading from dovecot-core 2.2.13-12~deb8u4 (jessie) to 2.2.27-3+deb9u2
(stretch),
we are seeing this issue appearing again on a few of our customer mailboxes
with lots of
entries inside mail.log. It seems that in our case especially large mailboxes
containing older
emails dating back a few years are affected.
We already tried to rebuild dovecot mailbox cache by stopping the dovecot
service
and deleting the dovecot.index.cache without success:
find /var/mail -name 'dovecot.index.cache' -exec rm {} \;
Any sugesstions on how to debug this issue?
Regards
Dominic
