Ensure emails are accounted for
Sysadmins often set up scripts that send back "OK" or "Error" emails, but there is no mechanism to send alert if *no* email was received for certain time period. Lack of such emails might indicate serious system failure somewhere, that becomes obvious when it is too late to do anything. There are many stories on internet about backups that were set up properly, but for some reason were disconnected.
Thus I wrote the script ensure_accounted_for.py that informs sysadmins about emails that were supposed to arrive on daily basis, but for some reason did not. Its sample configuration can be taken from ensure_af.cfg.