[svlug] botnets

[Rick Moen]

Quoting Chris Miller (lordsauronthegreat at gmail.com):

> I'm currently nurturing my own little brainchild solution to fix the
> proliferation of spam-sending botnets (just the spam part, nothing
> else.)  It hinges on the answer to this question:
> 
> When I send mail to my email server (smtp.gmail.com) it goes through
> as SMTP traffic, no?  So, when GMail sends that mail to my brother's
> email server (comcast.net), doesn't it use a different protocol?  I
> don't know.

It would indeed use SMTP -- and, if you want to know the exact routing,
have your brother send a copy back _with full headers_, and you'll see
every SMTP hop your mail went through.

Comcast's public-facing SMTP hosts' DNS hostnames will of necessity be
in the public DNS.  Just use "dig" and ask for their MX records, like
this:

:r! dig -t mx comcast.net +short

5 gateway-a.comcast.net.
5 gateway-r.comcast.net.
5 gateway-s.comcast.net.

-- 
Cheers,                               I remember Fred, 1919 - 2005. 
Rick Moen                        http://linuxmafia.com/faq/Essays/fred.html
rick at linuxmafia.com