I have an account using exchange email. There domain has become infected somehow. Two of the users are getting regular spam and the MX Lookup tool has had their account on suspended with some of the companies. This is what has been done:
1. Full virus and malware scans (21 infections killed) on all the machines using the domain.
2. Changed all of the machine passwords
3. Restored the reference to any companies listing the domain on the blacklist (CBL)
4. Registered the domain with emailreg
Two of the clients are still getting up to 150 spam emails a day. They are going directly into the junk mail account but we need to stop the access. Is there a way this can happen?