James Hess wrote:
Preventing hosts from just SMTP'ing out just anywhere they like
creates a new hurdle
for any infection to get over to spread; now any malware suddenly
needs to figure out a
SMTP server to use, and a username and password to use with SMTP
authentication,
and any other restrictions imposed by the ISP outgoing MTA.
This sounds great, except it doesn't scale. My router says there is no
noticeable difference between tcp/25 and tcp/445, or udp/134 or udp/1434 or
tcp/1025, or tcp/80. It asked if we should just block all ports and force people
through proxy servers. Why mitigate one vector when you can take them all out?
What makes SMTP so special a vector?
Yes, my router speaks. Yours doesn't?
Jack
