SMTP Port Blocking: Success or Failure?

Sun Feb 27 16:19:52 UTC 2005

>What about rate limiting SMTP traffic rather than blocking it? That
>could allow legitimate use for most private customers, while
>preventing bulk traffic.

Comcast has been doing something like that, looking for spikes of SMTP
connects and blocking when they see them, done at the IP level.  I
can't say that I'm overly impressed with how well it's working, but
it's better than nothing.

Regards,
John Levine, johnl at iecc.com, Primary Perpetrator of "The Internet for Dummies",
Information Superhighwayman wanna-be, http://www.johnlevine.com, Mayor
"I dropped the toothpaste", said Tom, crestfallenly.