Title: Message
Hi all. We are
having a problem with one company trying to send mail to us. They get NDRs when
trying to send some messages with Excel attachments to us. However when they try
to send the message again, eventually it gets through (or so they
say)
It seems that a
timeout occurs during the message transmission. Their server says DATA. We say
go ahead. Then it is hard to tell what happens, but probably their server never
hears our "go ahead" because it seems that it is not sending any data.
Eventually our server gets tired of waiting for data and sends 421 timeout.
Funny, but their server can hear that. Also it must have heard the previous mail
from and rcpt to responses as they got all the way to the Data statement. Of if
it is not a case of hearing problems, then why would their server just sit there
and not send anything?
Our mail server is
Exim, theirs is Postfix by the way.
Why does their
server not attempt to retry if it got 421 back? Isn't 4.x.x supposed to suggest
a retry? It seems that if their server attempted a few retries, eventually it
would succeed (just like the users when they keep on resending the
message)
Also there is a
permanent 5.0.0 error in the NDR. Which one is the right one - 5.0.0 or 4.2.1?
Or is it that our server says 4.2.1 and their server decides to interpret
it as 5.0.0 and "I ain't gonna retry this one"?
-----Original
Message-----
From: System
Administrator
Sent:
Thursday, March 11,
2004 7:51
AM
To: validuser@citco.com
Subject: Undeliverable: FW: Two Sigma
drafts for Thursday's meeting...
Your message did not reach some or
all of the intended recipients.
Subject: FW: Two Sigma drafts for Thursday's meeting...
Sent: 3/11/2004 7:43
AM
The following recipient(s) could
not be reached:
validuser@citco.com on
3/11/2004 7:51
AM
The e-mail system was unable to deliver the message, but did not report a
specific reason. Check the address and try again. If it still fails,
contact your system administrator.
< gw1.twosigma.com #5.0.0 X-Postfix; host
ftl1smtp01.citco.com[208.219.172.67] said: 500 server response
error, code 421 (in reply to end of DATA
command)>
