Page 1 of 1

Cannot receive external mail; cannot telnet to port 25

Posted: Thu Aug 11, 2005 4:43 pm
by dplaza
We are evaluating Scalix, but I am unable to get inbound external mail to work. If I telnet to port 25 on the Scalix server I connect and recieve a response. If I try it from another machine on the same lan, same subnet, I cannot. There is nothing between the machines but a network switch. I can ping and access webmail and sac from the machine but not port 25. ClamAV and spam assassin are installed (Yes, I know I should have tested the basics before adding complexity).

If I enter netstat -an | grep :25 | grep tcp I get:
tcp 0 0 192.168.0.20 0.0.0.0:* LISTEN
tcp 0 0 192.168.0.21 0.0.0.0:* LISTEN
tcp 0 0 127.0.0.1:25 0.0.0.0:* LISTEN

I am sure this is probably something simple, but to me it looks like it should be responding.

Posted: Thu Aug 11, 2005 5:49 pm
by ScalixSupport
The last line of the netstat output shows the problem. You only have a listener on port 25 of the localhost IP address.

This is probably down to the fact that you only have sendmail currently running and not the Scalix SMTP Relay.

Using

omstat -a

should indicate that the SMTP relay is running. If not, you will need to start it with

omon smtpd

This will bind to all available SMTP ports apart from 127.0.0.1.

Cheers

Dave

Posted: Thu Aug 11, 2005 5:52 pm
by ScalixSupport
The better command to run in these circumstances is:

lsof -i tcp:25

This will show you which processes are using that port.

Cheers

Dave

Posted: Fri Aug 12, 2005 9:50 am
by dplaza
My bad! I mis-typed the results. It should have been:

tcp 0 0 192.168.0.20:25 0.0.0.0:* LISTEN
tcp 0 0 192.168.0.21:25 0.0.0.0:* LISTEN
tcp 0 0 127.0.0.1:25 0.0.0.0:* LISTEN

The other results bring up:

sendmail 3797 root 4u IPv4 3964 TCP localhost.localdomain:smtp (LISTEN)
sendmail 3797 root 5u IPv4 3965 TCP 192.168.0.21:smtp (LISTEN)
omsmtpd 3936 root 4u IPv4 4247 TCP scalix1.domainname.net:smtp (LISTEN)

omstat -a returns

PC Monitor Started NON-STOP 0
Directory Relay Server Started 09:15:35
Notification Server Started 09:15:35 0
Shared memory daemon Started NON-STOP
Notification Monitor Started NON-STOP
Session Monitor Started NON-STOP
Container Access Monitor Started NON-STOP
Item Structure Server Stopped
Database Monitor Started 09:15:35
Licence Monitor Daemon Started NON-STOP
LDAP Daemon Started 09:15:35
Queue Manager Started NON-STOP
Item Delete Daemon Started NON-STOP
IMAP Server Daemon Started 09:15:35
SMTP Relay Started 09:15:35
Mime Browser Controller Started 09:15:35

I still cannot connect to port 25 via telnet except from the scalix server itself where I can connect to either 192.168.0.20 or 192.168.0.21 or hostname or fqdn, all with no problem.

Posted: Fri Aug 12, 2005 11:18 am
by ScalixSupport
dplaza wrote:
sendmail 3797 root 4u IPv4 3964 TCP localhost.localdomain:smtp (LISTEN)
sendmail 3797 root 5u IPv4 3965 TCP 192.168.0.21:smtp (LISTEN)
omsmtpd 3936 root 4u IPv4 4247 TCP scalix1.domainname.net:smtp (LISTEN)

I still cannot connect to port 25 via telnet except from the scalix server itself where I can connect to either 192.168.0.20 or 192.168.0.21 or hostname or fqdn, all with no problem.


This sounds more like a firewall problem.

Can you post the output of

iptables -L


Cheers

Dave

Posted: Fri Aug 12, 2005 2:06 pm
by dplaza
I have the firewall disabled;

Chain INPUT (policy ACCEPT)
target prot opt source destination

Chain FORWARD (policy ACCEPT)
target prot opt source destination

Chain OUTPUT (policy ACCEPT)
target prot opt source destination

Posted: Fri Aug 12, 2005 2:11 pm
by ScalixSupport
OK, so we've discounted a firewall on the Scalix server.

Looking at the lsof output, it appears that you cannot do a reverse DNS lookup for 192.18.0.21.

From the other servers, this may indicate a DNS or routing issue.

Does traceroute show that you are going directly to the Scalix server, does the hostname resolve to the correct IP address ?

You have processes listening on the ports so I'd be surprised if you were getting Connection Refused errors. I'm assuming that you just don't get any response at all.

If there are Connection Refused errors, this would indicate that you are not being routed to that server at all.

If you have edited /var/opt/scalix/sys/smtpd.cfg, can you post it ?

Cheers

Dave.