Is it possible to configure zimbra to alert administrator if any account exceeds defined send volume?
For scenario I'm thinking, let's say that administrator creates alert level at 30 messages per hour.
If any user sends more than 30 messages during one hour, alert email is sent to administrative email.
Point for this alert setting is to catch hacked account early. If certain account is sending massive amounts of mail, administrator can intervene and investigate why. Of course someone might have legit reason for sending high amounts of mail, but it's just question of finding the right alert tolerance for your system.