Starting at 1 am 10/23/06, yahoo.com began deferring all of the mail 
from our server (shamash.org[12.107.129.86])) with  "Deferred: 421 
Too many recipients"

We reported this on 10/23/06 via phone and were told to email 
[log in to unmask], which we did.  We still have not heard 
back from yahoo.com's postmaster.  When we called, we were told that 
we could not speak to anyone in the NOC/Abuse/Postmaster staff unless 
we had the name of a "non-executive employee that worked in that department".

A few questions for fellow ListServ site managers:
1) We have always sent out 50 messages per SMTP transaction.  How 
many do you send out per message?
2) It seems as though yahoo put into place a new multiple-recipient 
policy.  Do they publish these policy changes anywhere?  (is there an 
email list we can join)  Does any other site know what yahoo's 
current limit on RCPT in a single message?
3) Can someone mail me (not the list) the name (and/or email address) 
of some human in yahoo's Abuse/NOC/Postmaster department so I can 
reach someone?
4) Have you implemented Domain-Keys for ListServ? If so do you sign 
all of the mail which goes through ListServ, or only mail which 
originates from the server (administrative mail, digests, indexes)

-- 
   David Rosenthal, D.O.
   Shamash Coordinator http://shamash.org