[Dovecot] SSL/TLS with Outlook client

[Stuart Auchterlonie]

Kyle Wheeler wrote:
> On Wednesday, November 14 at 10:51 PM, quoth Marcus Rueckert:
>> rejecting on wrong informations in HELO/EHLO saves me lots of spam.
> 
> That's a half-baked idea at best, given that you're violating a MUST NOT 
> in the SMTP specification. Plus, how do you judge "wrong"? Hotmail and 
> MSN both fail to use their FQDNs in their HELO arguments---technically 
> that's wrong. I suppose you reject all hotmail.com email?
> 

It's easy to reject on things that clearly aren't configured.

HELO localhost ?? nah, that's junk.
SpeedTouch.lan <- dodgy USB modem if ever i saw one

spammers also quite often helo with
1. the name of your MX
2. the ip of your MX

neither of which should come from the outside.


So it's not so much about rejecting based on not being able to
lookup the helo'd name, it's more about reject based on things
that shouldn't be said to your server...


Stuart