auto ignore/whitelist option

[Sandor]

I'm not sure exactly how to call it.
I have the same problem on multiple server, we are giving email services to a company which has 10+ person working in an office . The office connects to the internet via a NATing router, so everybody is seen coming from a single IP.
Now if a single person fails his password a couple time from , that IP will be banned, and everybody will loose access .
So suggestion : if in the last x minutes, there were multiple good logins from an IP from different users, then ignore login failures from that IP for a couple hour. maybe make as option so can be disabled/enabled as needed.

[Silent Ninja]

Why not just add the remote IP of the router as a whitelisted / ignored IP?
Do you have a dynamic IP?