Re: Domainkeys and ISPs

[Michael Sprague <mfs@saneinc.net>]

On Wed, Mar 12, 2008 at 12:26:23PM -0700, cls@truffula.sj.ca.us wrote:
> [This message has also been posted to linux.debian.isp.]
> In article <a6zce-5UT-27@gated-at.bofh.it>, Michael Sprague wrote:
> >
> > Second, let's say spammer@spammer.com sends a message to
> > user@example.com and it gets by our spam filtering.  We forward to
> > user@yahoo.com.  If we sign it, are we helping spammer.com in any way?
> 
> It seems to me DKIM is just not compatible with forwarding,
> for that reason.  Most of my users have mailbox and outbound
> relay service from their ISPs.  They use the domains they
> host with me partly to hide that fact.  
> 
> When Yahoo requires DKIM, I just won't let
> my users forward to Yahoo any more.  They'll have to choose
> send through my SMTP-AUTH and receive through Yahoo with DKIM,
> or send their usual way and receive here or elsewhere.
> 
> (What a shame.  Forwarding is straightforward,
> while SMTP-AUTH is poorly documented and standardized.
> *Try* to find complete, correct, and current instructions for
> setting it up and running it on Debian!)
> 
> There is already a forwarding issue with AOL.  I can't stop
> all the spam, and when I forward it the AOL user sometimes
> generates a "SCOMP" spam report.  AOL doesn't believe my
> Received line, as well they shouldn't, so they credit the
> spam to me.
> 
> Maybe forwarding just isn't going to be practical any more.

I have to agree.  Most of our problems are from forwarding.  We don't
want to take away that ability because I know we'll lose customers.  But
if it get so bad that it takes 12 hours to send a message to Yahoo, we
may have no choice.  

Yahoo says they'll sort of talk to you if you use DomainKeys to sign
messages.  That brought up the other issue which is the reason for this
thread.  But it's not Debian specific so we don't need to continue it if
y'all don't want to.  :)

thanks,
mike

-- 
Michael F. Sprague     | mfs@saneinc.net
http://www.saneinc.net | System and Network Engineering (SaNE), Inc
Providers of the SpamOnion anti-spam service