[afnog] Problems Sending Mail to Yahoo

[Joe Abley]

On 10 Apr 2008, at 13:00 , Peter Nyamukusa wrote:

> I am just wondering if any of you are having issues sending email to  
> yahoo
> especially if you are an ISP. I noticed as of yesterday most of the  
> mail to
> yahoo is deferred and little trickles out at a snails pace. It seems  
> a while
> back they implemented some form of Grey-listing in order to help  
> fight spam.
> Any comments/feedback welcome

I've had similar problems with my personal mail servers.

The last time I looked, the URLs reported in the 421 messages from  
Yahoo! MTAs didn't work (they redirected to generic support pages); I  
searched NANOG archives to find the right URLs, but even then it  
wasn't obvious which of their various forms I was supposed to be  
filling out.

One of the reasons I ran into trouble (I think) was that I had some e- 
mail aliases set up which expanded to lists of people, and some of  
those people had Y! accounts. When spam hit that alias and was  
forwarded, the Y! MTAs apparently assigned some portion of the  
responsibility for the spam to my MTAs, which I guess is somewhat  
reasonable since from the perspective of Yahoo! they probably looked  
like open relays.

I have been told that even if you take great care to correct whatever  
problem caused your server to be considered suspect, all it takes is  
two or more Y! mail users to press the "this is spam" button on mail  
sent through your server and you're back to square one.

The most recent thing I tried was reconfiguring the MTAs I use to  
submit mail through so that they add DomainKeys headers to my outbound  
mail, and adding the corresponding records to the DNS for the domains  
concerned. This seems to have made things better, for now.

In case you want to try DomainKeys too, it turned out to be very easy  
to do with exim on FreeBSD. The following link has some useful  
information:

   http://wiki.exim.org/DomainKeys

Skip down to the heading "Yahoo DomainKeys for Exim + FreeBSD + bind  
name server howto" and read from there.


Joe