On 5/11/11 4:14 PM, David F. Skoll wrote:
Do you have evidence to back up that claim? I don't believe
it's true. We use greylisting and Yahoo's servers don't seem
to have problems with it.
what I have observed; (no, we don't greylist)
but, we do keep a cluster of 4 mx servers per client. each one with
different bl, timing, available smtp connections, etc.
if someone sends an email to 175 people, once they hit 'x' number in the
first email attempt, we send '4xx too many emails'
ie:
ehlo *.yahoo.com
mail from: <some...@yahoo.com>
rcpt to: <one>
250 ok
rcpt to: <two>
250 ok
[skip to 100].
rcpt to: <onehundered>
4xx too many
RFC'S seem to indicate that they should send a data command next and
send the email to be delivered to the first 99, then try the next 51 on
the next highest mx.
doesn't happen on yahoo.com
they drop the connection, and try again at next highest mx, then on mx4,
bounce the email back to sender with the last mx's ip in the error
message and the 4xx too many
aol does something similar also, but will send the first 'x' number of
emails, and MAYBE later send the rest.
--
Michael Scheidell, CTO
o: 561-999-5000
d: 561-948-2259
ISN: 1259*1300
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