Already searched some Hours about this Problem - but no good Solution in sight - so maybe someone here can help me on this.
We offer Webhosting / Mail Services. Lately the amount of Hacked E-Mail Accounts of our Customers is raising (Virus, Trojan, ...) - their SMTP Account Data is stolen and our Mail-System is abused by sending Spam through SMTP-Verificated Accounts ... Which, of course, is a big Problem for our IP-Reputation ...
How can we detect such hacked Accounts faster than waiting for Abuse Records? (Sendmail, Postfix) Are there Tools for behavioural Detection on Accounts? Or some other Services? Or what would be the right approach for such problems?
Hope someone here can hint me in the right direction.