I have an email server that I use to host email for several companies. Somebody must have sent something out or someone has a virus that flagged our server to be listed on a blacklist.
How can we combat this? How can we make sure that people using our server does not get it blacklisted? I certainly cannot be going around checking every PC from every company for viruses that uses my mail server.
Is there any sure way to prevent others behavior from flagging my server?
I have good policies setup that require authentication and my server is not an open relay.
Does anyone know of any good sites that check a large amount of blacklists?