We have started seeing that users that are no longer with the company and their mailbox has been disabled. If there is a server side rule for that user to forward a message when it arrives. The rule is still active even thought the account is disabled. Is there a way to stop this besides logging in as the user and killing all the rules ro deleting the user?

A user created server side rule can send canned reply in response to receiving an email, but I don't believe it can forward an email. This sounds more like a hub transport rule, or an alternate recipient set up on the mailbox.

The "path of least resistance" would probably be to create a DL for terminated users, and a hub transport rule to drop any email from members of that DL.

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