Lost input channel error

[mosc]

I'm running RedHat 7.2 with Sendmail 8-11-6.3
I'm getting a Lost input channel after Mail error. Here is an example from my maillog:

Mar 29 06:42:05 mail sendmail[4634]: h2TBfY704634: lost input channel from out015p
ub.verizon.net [206.46.170.90] to Daemon0 after mail

Mar 29 06:42:05 mail sendmail[4634]: h2TBfY704634: from=<diapers3@gte.net>, size=1
37033, class=0, nrcpts=0, proto=ESMTP, daemon=Daemon0, relay=out015pub.verizon.net
[206.46.170.90]

This message is not delevered to the local user.

This error only occurs on mail from certain servers, many other servers are getting through fine. The servers that run into this error never get a message through. Does anyone have any idea as to what causes this problem, and how to resolve it?

Thanks in advance

 

[MRobare]

MOSC: did you ever get an answer to your question?
I have a similar problem but I suspect a possible Firewall config. causing the problem. Although that does not appear to make sense.

Thanks.
MR

 

[mosc]

MRobare,
No, no one ever responded to this post. I was so desparate that I installed a RedHat 9 server with the latest version of sendmail that RedHat provides. That seems to have solved the problem.
mosc

 

[MRobare]

MOSC,
Thanks for the reply. I'm new to Linux but I am told
that we are using ver. 9.
Oh well....I'll keep digging.

MR

 

[mosc]

MR,

Well, moving to Red Hat 9 and upgrading sendmail to the latest version helped me. An email wizard I know told me that this is usually indicative of a problem on the server that is sending mail. This is not an acceptable answer when the server is verizon.net .

I wish I could provide more help. The fact that it's so hard to get people to help with sendmail problems may be trying to tell us something. Maybe sendmail is past its prime and it's time to look for something better. I know the answer is not MS Exchange though...

 

[Rhinokiller]

Did you check to see if you are listed by the DSBL ?

http://www.dsbl.org

What happens is that the real spammer is sending messages to addresses that some times no longer exist and hang the TCP connection with sendmail SMTP server before the server has time to report that the address is undeliverable. Then sendmail mails back the address in the envelope sender with that message of lost input channel.

The problem is that the spammers are using addresses of valid sites as envelope sender address, so sites that have nothing to do with spamming are getting a lot of garbage lost input channel messages and are even being black listed probably like your site.

There is no solution for this except convincing sendmail developers to disable by default that useless feature of mailing the envelope sender address with lost input channel report messages.


There is no God, only 10001010