Hello,

I've had the problem from the Ubuntu rsyslogd Bug: https://bugs.launchpad.net/ubuntu/+sour … bug/407862

After logrotate was launched the rsyslogd was not writing anymore in the mail (and other) logs.

I've solved it modifying the /etc/logrotate.d/maillog

at the line where it re-creates the logs to:
create 0640 syslog adm

and making a
chmod 0640 /var/log/mail*

and a
chown syslog:adm to /var/log/mail*

(I also did the same thing for MySQL logs that had the same problem)
Now everything seems to work correctly.

Hope it helps someone

Alberto