I have a client who has been infected with the Antimalware Doctor crap. As I was running Malwarebytes on the computer a couple of others started reporting problems with their emails. They are reporting the following errors:
There was a SMTP communications problem with the recipients email server.
<xxxx.com #5.5.0 smtp;550 Recipient Rejected: Access Denied: xx.xx.xx.xx blocked by composite list>
Can anyone please shed some light on the fix here? They are using a Small Business Server 2003.