Following the update I did today, I had to reset permission to a file:
chmod o+x /usr/lib/cyrus-imapd/deliver
The error message concerning this was:
preline:_fatal:_unable_to_run_/usr/lib/cyrus-imapd/deliver:_access_denied/preline:_fatal:_unable_to_copy_input:_broken_pipe/
The permissions are:
Before
-rwsr-xr-- 1 cyrus mail 758800 jui 25 09:08 /usr/lib/cyrus-imapd/deliver
After
-rwsr-xr-x 1 cyrus mail 758800 jui 25 09:08 /usr/lib/cyrus-imapd/deliver
Based on the dates, the file does not seem to have changed, but the permissions changed.