Exim - remote_smtp defer -- Help!

[bmcpanel]

A customer contacted me today and told me his mail is not making it to on particular person he sends to on a regular basis. He says the person he sends to reports that he is receiving mail from other people, just not from my customer.

I found the message in the exim queue and tried to send it using the WHM. Below is the info that was printed to the screen. Sending does fail. Can someone tell me what might be going on? Thanks.
-----------------------------------------------
Message 1IQNqz-0001T6-GC is not frozen
delivering 1IQNqz-0001T6-GC
Connecting to mail-fwd.g14.rapidsite.net [128.121.85.2]:25 ... connected
SMTP<< 220 mx29.mlpsca01.us.mxservers.net ESMTP mxl_mta-1.3.8-10p4; Fri, 31 Aug 2007 14:00:56 -0400 (EDT); NO UCE
SMTP>> EHLO ns.myserver.net
SMTP<< 250-mx29.mlpsca01.us.mxservers.net
250-SIZE 0
250 PIPELINING
SMTP>> MAIL FROM:<Virgil@mycustomersite.com> SIZE=490232
SMTP>> RCPT TO:<something@issrating.com>
SMTP>> DATA
SMTP<< 250 Sender Ok
SMTP<< 250 something@issrating.com ok (normal)
SMTP<< 354 Start mail input; end with <CRLF>.<CRLF>
SMTP>> writing message and terminating "."
LOG: MAIN
Remote host mail-fwd.g14.rapidsite.net [128.121.85.2] closed connection in response to sending data block
LOG: MAIN
== something@issrating.com R=lookuphost T=remote_smtp defer (-18): Remote host mail-fwd.g14.rapidsite.net [128.121.85.2] closed connection in response to sending data block

[bmcpanel]

A customer contacted me today and told me his mail is not making it to on particular person he sends to on a regular basis. He says the person he sends to reports that he is receiving mail from other people, just not from my customer.

I found the message in the exim queue and tried to send it using the WHM. Below is the info that was printed to the screen. Sending does fail. Can someone tell me what might be going on? Thanks.
-----------------------------------------------
Message 1IQNqz-0001T6-GC is not frozen
delivering 1IQNqz-0001T6-GC
Connecting to mail-fwd.g14.rapidsite.net [128.121.85.2]:25 ... connected
SMTP<< 220 mx29.mlpsca01.us.mxservers.net ESMTP mxl_mta-1.3.8-10p4; Fri, 31 Aug 2007 14:00:56 -0400 (EDT); NO UCE
SMTP>> EHLO ns.myserver.net
SMTP<< 250-mx29.mlpsca01.us.mxservers.net
250-SIZE 0
250 PIPELINING
SMTP>> MAIL FROM:<Virgil@mycustomersite.com> SIZE=490232
SMTP>> RCPT TO:<something@issrating.com>
SMTP>> DATA
SMTP<< 250 Sender Ok
SMTP<< 250 something@issrating.com ok (normal)
SMTP<< 354 Start mail input; end with <CRLF>.<CRLF>
SMTP>> writing message and terminating "."
LOG: MAIN
Remote host mail-fwd.g14.rapidsite.net [128.121.85.2] closed connection in response to sending data block
LOG: MAIN
== something@issrating.com R=lookuphost T=remote_smtp defer (-18): Remote host mail-fwd.g14.rapidsite.net [128.121.85.2] closed connection in response to sending data block

Desperation bump...

[nyjimbo]

Well it looks like mail-fwd.g14.rapidsite.net may be implementing some kind of reject-spam-at-smtp-connect or something like it. Since they seem to not disconnect immediatly but rather at time of sending the message itself.

Can you send an email from that same server to your clients intended remote receiver address as a test to see if it goes through.

Also if you can get console on the server that is sending and then use it to telnet to the mail-fwd.g14.rapidsite.net 25 port see if it kills you off immediatly with a 421 or other "try again later" or if it will accept normal commands. But I kind of think it could be thinking the email is spam and disconnecting.

[bmcpanel]

Well it looks like mail-fwd.g14.rapidsite.net may be implementing some kind of reject-spam-at-smtp-connect or something like it. Since they seem to not disconnect immediatly but rather at time of sending the message itself.

Can you send an email from that same server to your clients intended remote receiver address as a test to see if it goes through.

Also if you can get console on the server that is sending and then use it to telnet to the mail-fwd.g14.rapidsite.net 25 port see if it kills you off immediatly with a 421 or other "try again later" or if it will accept normal commands. But I kind of think it could be thinking the email is spam and disconnecting.

I noticed that also. The connection goes fine until the writing, which I assume is when the receiver server reads the content of the email. I am still working with the client to find out as much as possible about the reject on their end.

[chirpy]

But I kind of think it could be thinking the email is spam and disconnecting.

That seems the most likely. It's almost definitely a problem at the other end of the SMTP connection.

[bmcpanel]

Thanks for the replies. The problem cleared up today for some reason. Nothing changed on our end, so I can only assume the issue was on the other end and has been resolved.