Dealing with SPAM WAS has my system been compromised?

[Darrin Chandler]

On Thu, Sep 14, 2006 at 09:24:20PM -0700, George Toft wrote:
> I find that very few domains use SPF records.  Neat idea, but 99% of the 
> domains have not set them up and most mail servers don't care.

I've been using greylisting for a good while now and it works well
except for one thing: large email services (Yahoo!, Hotmail, Gmail) use
a large number of outgoing mail servers. 10 get whitelisted fine and
then somebody is waiting on an email and it's one of the odd ones from
gmail stuck in the greylist. gmail does spf, and so do most of the
others. Whitelisting spf IPs from major email providers fixes that.

SPF can help. It's pretty fast and easy. Best of all, it really doesn't
*hurt* anything. If there are no SPF records then you don't do anything.
But if someone's claiming to be from gmail.com and the IP isn't in the
SPF then you know it's bad.

-- 
Darrin Chandler            |  Phoenix BSD Users Group
dwchandler at stilyagin.com   |  http://bsd.phoenix.az.us/
http://www.stilyagin.com/  |