I assume that you are getting all mail via MercuryS.

The first thing that comes to mind is that the RCPT TO: address is not the same as the From: address. 

The second is that you deleted the user with Mercury/32 running and did not use the CTRL+Manage local users and/or restart Mercury so that the address was not deleted from memory.

Changing of the IP address should have no affect on this.

I am using Mercury/32 v4.6 and PopFile Control Center to filter our mail

I have a local user that I have tried to eliminate all incoming mail - so far it hasn't worked - I have deleted the address using manage local users

I also went to Configuration / Mercury SMTP Server / General and made sure that "Accept mail for invalid local addresses" was unchecked

I am still getting messages getting through to the the specific address.

I am at a loss - I even created filters after all the above and I am still having troubles

Our phone company recently changed our IP address - would that have anything to do with my problem

 Any insight would be greatly appreciated - I am fairly new to managing a mial server

 KC