Bug 53264 - Sendmail refuses connections from everywhere except "localhost"
Sendmail refuses connections from everywhere except "localhost"
Product: Red Hat Linux
Classification: Retired
Component: sendmail (Show other bugs)
i386 Linux
high Severity high
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Assigned To: Florian La Roche
David Lawrence
Depends On:
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Reported: 2001-09-05 15:09 EDT by Alan Hoyle
Modified: 2005-10-31 17:00 EST (History)
0 users

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Fixed In Version:
Doc Type: Bug Fix
Doc Text:
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Clone Of:
Last Closed: 2001-09-05 15:09:18 EDT
Type: ---
Regression: ---
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Verified Versions:
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oVirt Team: ---
RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: ---

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Description Alan Hoyle 2001-09-05 15:09:14 EDT
Description of Problem:

My machine is named "nelson.oit.unc.edu."  When I run "telnet localhost 25" I get the appropriate "ESMTP" response.  However when I run "telnet nelson.oit.unc.edu 25" I get a "connection refused" error message.  I get the connection refused message when I try this from the local machine or from a remote machine.  The only change I've made to the sendmail configuration from the default is that I've added "nelson.oit.unc.edu" and "nelson" to /etc/mail/local-host-names.  I originally suspected the problem might be related to ipchains or my TCP_wrappers configuration, but that seems not to be the case.  (I've tried stopping ipchains with "/etc/init.d/ipchains stop" but the problem persists.)

My /etc/hosts.allow file reads "sendmail :  ALL"

my /etc/sysconfig/ipchains file reads as follows:

# Firewall configuration written by lokkit

# Manual customization of this file is not recommended.

# Note: ifup-post will punch the current nameservers through the

#       firewall; such entries will *not* be listed here.

:input ACCEPT

:forward ACCEPT

:output ACCEPT

-A input -s 0/0 -d 0/0 25 -p tcp -y -j ACCEPT

-A input -s 0/0 -d 0/0 80 -p tcp -y -j ACCEPT

-A input -s 0/0 -d 0/0 22 -p tcp -y -j ACCEPT

-A input -s 0/0 -d 0/0 -i lo -j ACCEPT

-A input -p tcp -s 0/0 -d 0/0 0:1023 -y -j REJECT

-A input -p tcp -s 0/0 -d 0/0 2049 -y -j REJECT

-A input -p udp -s 0/0 -d 0/0 0:1023 -j REJECT

-A input -p udp -s 0/0 -d 0/0 2049 -j REJECT

-A input -p tcp -s 0/0 -d 0/0 6000:6009 -y -j REJECT

-A input -p tcp -s 0/0 -d 0/0 7100 -y -j REJECT


Version-Release number of selected component (if applicable):

Sendmail 8.11.2/8.11.2

How Reproducible:

Every time

Steps to Reproduce:

telnet nelson.oit.unc.edu 25  

Actual Results:


telnet: Unable to connect to remote host: Connection refused

Expected Results:

220 nelson.oit.unc.edu ESMTP Sendmail 8.11.2/8.11.2; Wed, 5 Sep 2001 15:08:12 -0400

Additional Information:

I need to have this resolved by Friday, September 7 or I will have lost all of the mail that's been sent to my address since Monday, Sept 3.
Comment 1 David Lawrence 2001-09-06 10:26:37 EDT
Have you made any changes to your /etc/sendmail.cf file to allow remote
connections? Red Hat by default ships sendmail to only allow connections from
localhost for security reasons. You can easily fix this by editing a line in 
/etc/mail/sendmail.mc and then recreating your /etc/sendmail.cf file from that.

In /etc/mail/sendmail.mc change the following line

DAEMON_OPTIONS(`Port=smtp,Addr=, Name=MTA')


dnl DAEMON_OPTIONS(`Port=smtp,Addr=, Name=MTA')

The part 'dnl' is the same as comment a line out. After saving the above change
then execute 

m4 /etc/mail/sendmail.mc > /etc/sendmail.cf

Restart sendmail and you should be able to receive mail remotely. Reopen this
bug report if you do not have positive results.

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