Keith Moore followed up:
On Aug 27, 2011, at 9:53 AM, Keith Moore wrote:
Maybe the spammers are trying to deal with greylisting?
For that matter, I wonder if legitimate senders are trying to deal
with greylisting also. Maybe there are poor implementations of greylisting
that block legitimate traffic too often. Maybe there are some large-volume
senders that don't want to deal with having greylisted mail in their queues
any longer than necessary. If retrying after a few seconds works on
some greylists, it's not surprising that some senders would start
doing it.
Agree, which makes it part of the dilemma because all (anonymous,
unauthenticated, unauthorized, non-prearranged) clients are now lumped
with "The Good, The Bad and the Ugly." Just saw the classic movie
again the other day. :-)
--
Sincerely
Hector Santos
http://www.santronics.com