pflogsumm has helped me identify problems that mailinabox status checks and other tools couldn’t.
It basically gives me a daily summary of postfix logs and thus highlights issues I would have usually never discovered like: domain/IPV6 related issues, PTR reverse ip issues, SASL authentication issues from a satellite postfix install, etc etc. I don’t use munin at all, I don’t find it useful in discovering issues.
It is easily installed via apt-get install pflogsumm and then I add it to my daily cron:
@daily /usr/sbin/pflogsumm -d yesterday --problems /var/log/mail.log | mail -s "Mail Server: Yesterday's mail activity" email@example.com
Perhaps this should be considered to be added to maillinabox, I’m sure it can be easily done, and it is really helpful.