Stephen J. Turnbull wrote:
Attila Kinali writes:
This is just selective greylisting, which lots of sites use as a blanket policy.
It's definitly not greylisting. Our server sends out a few dozen mails a day on the low traffic lists to a few hundred on the high traffic ones. Any greylisting that is half way sanely implemented should know after the second mail that the server is a legitimate sender.
Well, maybe. That is harder than it sounds to scale, though. The problem is that Yahoo has a lot of MXes, each handling hundreds of thousands or millions of messages per day, and they're going to need to propagate the greylist database to all of them somehow. It's a solvable problem, but nontrivial.
It may not be greylisting per se, but it actually doesn't seem to be a problem for my MTA. In response to this thread, I looked in my maillog and I see about 2500 of the "421 4.7.0 [TS01]" messages in the last month. I don't see any "421 4.7.0 [TS02]" messages. As far as I can tell, every one of these was eventually delivered, some almost immediately to a different MX, some a few hours later after several retries and some in between.
I wonder if Rick actually has a problem with undelivered (as opposed to delayed) mail, or if his hosting company is just concerned about the log messages and retries.
Also, the messages I see, and the message Rick posted all seem to come in response to the initial connect. Thus, Rick's hosting company should be looking at themselve rather than Rick's list since it is apparently the connect from the IP that is being delayed, not list mail.
-- Mark Sapiro <mark@msapiro.net> The highway is for gamblers, San Francisco Bay Area, California better use your sense - B. Dylan