[SWLUG] smtp authentication

[Steve Hill]

On 13/12/11 22:46, bascule wrote:

> what i don't understand is how yahoo know that i've authenticated to the
> virgin server in the first place, i can't see anything in the headers (which
> can of course be forged) to indicate this.

AFAIK they don't.  Yahoo have a whitelist of servers that are allowed to 
send to them (or maybe a blacklist of servers that aren't allowed to 
send to them).  In general, it is an almighty pain if Yahoo decide that 
they don't want to hear from your SMTP server because (in my experience) 
they won't tell you why they have blacklisted it and you go through hell 
to actually get someone to respond intelligently instead of just 
responding with form replies that don't actually help.  Doing domain 
keys on your SMTP server does help though.

Unfortunately it also only takes one idiot customer who decides to send 
spam(*) through my SMTP server and I end up back at square one trying to 
get it whitelisted on the likes of Yahoo and AOL again.

(* marketing departments of all sorts of companies forever seem to fail 
to understand that automatically subscribing everyone who's ever shown 
the vaguest interest in their products to their mailing lists is 
illegal, will end up with the SMTP server blacklisted and is a breach of 
their contract with me.  Unfortunately, the first I know that one of my 
customers has been a moron is when all the other customers start 
complaining that mails to yahoo et al are bouncing).

-- 

  - Steve