RE: how to block SMTP Commands without ISA Server

  • From: "John Tolmachoff \(Lists\)" <johnlist@xxxxxxxxxxxxxxxxxxx>
  • To: "'[ExchangeList]'" <exchangelist@xxxxxxxxxxxxx>
  • Date: Wed, 3 Dec 2003 10:45:49 -0800

> I don't know how to do this with Exchange, but in some firewalls (I know
> Raptor has it), you can block TELNET to port 25. What the firewall does,
> is time how long it takes for the commands to be entered. A mail server
> connecting to yours on port 25, would fire those commands quite
> rapidly, when a human would do this, it would be much slower. Based on
> this, the firewall blocks entering commands by hand.

That would then also block some one from using Telnet to diagnose a SMTP
connection problem.

John Tolmachoff
eServices For You

Other related posts: