Big SMTP problem

General Interworx Control Panel Info General Inquries
1

Since about the 10th May, my SMTP inbound daemon has stopped working.

As far as I know, noone has touched any config files for it or installed/removed any software. Ports 25 and 587 are open inbound and outbound on TCP, and closed in both directions on UDP.

There’s nothing I can see in the logs. Local deliveries work fine (ie. someone@somedomain.com to someoneelse@otherdomain.com, if both are hosted on that box) but nothing else works (at least not very well…))

I cannot telnet to the box on port 25. It just sits there doing nothing… and then closes the connection after about one minute, regardless of any input:

[root@yoda ~]# telnet localhost 25
Trying 127.0.0.1…
Connected to localhost.yoda.domain.org (127.0.0.1).
Escape character is ‘^]’.
Connection closed by foreign host.

Using port 587, the backup SMTP server, it seems to work… It delivers the mail when I telnet to localhost, but not if I use a different IP:

[root@yoda ~]# telnet localhost 587
Trying 127.0.0.1…
Connected to localhost.yoda.domain.org (127.0.0.1).
Escape character is ‘^]’.
220 TNet SMTP Server ESMTP
helo fr3d
250 TNet SMTP Server
mail from: fred@my-domain.org
250 ok
rcpt to: fr3d@dsl.my-isp.com
250 ok
data
354 go ahead
subject: test telnet smtp2
test
.
250 ok 1147648027 qp 1620
quit
221 TNet SMTP Server
Connection closed by foreign host.

[root@yoda ~]# telnet mail.my-domain.org 587
Trying 65.110.xx.xxx…
Connected to mail.my-domain.org (65.110.xx.xxx).
Escape character is ‘^]’.
220 TNet SMTP Server ESMTP
helo fr3d
250 TNet SMTP Server
mail from: fred@my-domain.org
250 ok
rcpt to: fr3d@dsl.my-isp.com
553 sorry, that domain isn’t allowed to be relayed thru this MTA (#5.7.1)
quit
221 TNet SMTP Server
Connection closed by foreign host.

However, it does work if I connect from a different box, using that same external hostname/IP.

My email client times out when trying to send a test email, using either port 25 or 587.

Any ideas? :confused:

Thanks in advance.

2

Hi Fr3d,

Can you check to see what is running on port 25 on your box? We’ve seen similar problems like this where another mail server, typically started through xinetd, takes over port 25.

Socheat

3

This is what I get:

[root@yoda ~]# netstat -npl | grep :25
tcp 0 0 0.0.0.0:25 0.0.0.0:* LISTEN 9803/tcpserver

tcpserver info:

[root@yoda ~]# whereis tcpserver
tcpserver: /usr/bin/tcpserver
[root@yoda ~]# ls -al /usr/bin | grep tcpserver
-rwxr-xr-x 1 root root 106424 Feb 23 2005 tcpserver

and the process:

[root@yoda ~]# ps ax | grep 9803
9803 ? S 0:00 /usr/bin/tcpserver -v -R -S -p -x /etc/tcprules.d/tcp.smtp.cdb -c 50 -u 108 -g 104 0 smtp /usr/bin/rblsmtpd -rbl.spamcop.net /var/qmail/bin/qmail-smtpd yoda.domain.org /home/vpopmail/bin/vchkpw /bin/true

4

Any ideas on a solution? We’ve been without email for close to 10 days :’(.

5

Fr3d, if you haven’t already please open a ticket.

Chris