Avagy: a spammerek már a spájzban vannak.
So what can you do to proactively prevent a client’s workstation to be turned into a spam spewing beast?
Les Connor and ISA Server 2004 once again to the rescue:
He builds a rule to deny any port 25 transmissions from anything other than the server itself and an internal scanner.Action: Deny, log requests Protocols: Selected : SMTP From: The lan (defined IP address range) Exceptions: SBS, Printer and Scanner IP's, which are defined specific IP addresses. To: Anywhere (pre-existing destination) Users: All Schedule: Always Caveat, this blocks the use of telnet <external host> 25 from any local machine for troubleshooting purposes, so beware of this if you use it on your *own* network for testing SMTP.You might also want to build an alert rule when this deny rule kicks in as it would be a sign of infestation.