Unix & Linux Stack Exchange is a question and answer site for users of Linux, FreeBSD and other Un*x-like operating systems. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I am using Zenoss for monitoring purpose. I have been using its mail service for a long time. Suddenly my mail service in zenoss stopped and started showing <class 'smtplib.SMTPServerDisconnected'> - Connection unexpectedly closed and no mails are outgoing. When I ran the mail command via CLI, the mail goes to the email address. While executing the zenoss script for mailer won't work and throws out the error as shown above.

My server is RHEL 5.3 x86_64, with Zenoss 4.2 & sendmail email server.

Sendmail logs & Zenoss email conf

Apr 11 07:14:30 XXXhostnameXX sendmail[13582]: r3BBDgia013582: lost input channel from localhost.localdomain [] to MTA after mail
Apr 11 07:14:30 XXXhostnameXX sendmail[13582]: r3BBDgia013582: from=<fromaddress@emaildomain.com>, size=146972, class=0, nrcpts=0, proto=ESMTP, daemon=MTA, relay=localhost.localdomain []

Zenoss is following basic smtp connection as emailing is done by local sendmail server (localhost) in port 25. No specific configuration is used.

share|improve this question
1) Could you post the relevant sendmail log entries? 2) Could you post details of your Zenoss email configuration? [It may help "non Zenoss" experts] – Andrzej A. Filip Apr 11 '13 at 11:16
@Andrzej A. Filip :Updated with logs. – Kratos Apr 11 '13 at 11:28

It may be is a client side timeout after issuing "MAIL FROM:".
Knowing exact value of reply delay should provide a valuable hint.

Could you send a test message in verbose mode? [It should provide SMTP session transcript]

# -v - be verbose (provide SMTP transcript)
# -i - 'single dot' line is NOT end of email
# -t - get recipients list from email headers
# -f - set envelope sender email address (for "MAIL FROM:" in SMTP session)
/usr/sbin/sendmail -v -i -t -ffromaddress@emaildomain.com <<END
Subject: test
From: fromaddress@emaildomain.com
to: xxx@example.net

share|improve this answer
Thank you .This script was really helpful in testing my sendmail .In its output , otherfew address unresolvable for @emaildomain.com , test email successfully reached xxx@example.net.Do you know a way to extend the time out in email Server side ? – Kratos Apr 12 '13 at 6:21
1) Add -8.20 sendmail command line option to trace DNS lookups. Fixing DNS entries or used email addresses may fix your problem. 2) I know sendmail, I do not know Zenoss. – Andrzej A. Filip Apr 12 '13 at 17:22

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.