Hello Everyone,
It's been a while since I posted on this topic, and unfortunately I'm still
having trouble with Yahoo deferrals. The links that were provided in this
post worked, but after the forms were received by what I *think* is a human
I still got a canned reply. I've tried replying with specific details about
our problem, but is either answered with another generic reply or not at
all. We are running Imall, and each domain has it's own IP address. Queue
Timer and Tries before returning to sender are set to 30 minutes / 5
attempts. According to yahoo they do want you to attempt to resend if you
get a 421 error. SPF is also set on a per-domain basis. I'm not sure what
else to try. Does anyone have a better understanding of how Yahoo
greylisting works?
Thanks in advance!
Justin Wilson
Hello,
Try encorporating DomainKeys and applying for their feedback loop.
http://help.yahoo.com/l/us/yahoo/mail/postmaster/forms_index.html
I still have the same problem. Do you have any users who forward their email to their free @yahoo.com addresses from your server?
Let me know if you get in touch with anyone 
-Ray
Do you have any users who forward their email to their free
@yahoo.com addresses from your server?
That is likely the core of Justin's problem.
We've found the way to minimize issues with yahoo mail are:
1. Clean up (ideally eliminate) the .forwarders on your end.
This requires some effort on your part to educate your
customers on how they are making their own lives
more difficult with their behaviors. Always a tough task.
2. Scour your outbound queues of garbage
"be conservative in what you send"
3. Agressive delivery retries, but early discards.
In other words, we've noted the yahoo MX machines seem to
operate their greylists independantly, so if one stops you
the next one may not. Don't wait too long before you retry
but dump mail after X hours if yahoo won't accept it. We've
settled on 6 hours. Any longer and it just stays backed up
forever.
Let me know if you get in touch with anyone 
-Ray
I agree with Ray on this one... I'll gladly buy a sushi lunch for the first real yahoo mail admin that ever appears in meatspace. I'm convinced that there are no real humans working mail ops there.
--chuck
Wearing my academic IT hat for a moment, a Real Person! (tm) appeared on
the HIED-EMAILADMIN list (hosted by nd.edu) earlier today, in answer to
a lot of talk about how bad things have got with Yahoo recently.
Out of politeness (since his email was obviously aimed at the list
membership, which isn't NANOG) I have asked if he minds my forwarding it
to other lists (well, I started with the mailop@mailop.org list, but
I'll work from there).
His title, not giving too much away, is:
Anti-Abuse Product Manager
Yahoo! Mail
And you may, or may not, find his details in the list archives of the
first list I mentioned above.
I hope someone finds my not mentioning this fruitful
Graeme