Unable to relay mail

timinator · 11-17-2017, 10:14 AM

Hi, we have a Unix server that uses our Fedora Linux box to relay mail. This has worked in the past. The unix server is listed in the /etc/mail/access file. When I do a test email from unix to Fedora I get the following messages:

"Connecting to [172.17.X.X] via relay.....Connection refused by [172.17.X.X].

Any suggestions would be appreciated - thanks

scasey · 11-17-2017, 12:08 PM

If 172.17.X.X is the IP address of the Linux server, I'd guess that you don't have an MTA running on that server...but that's just a WAG. Please tell us:
The MUA being used on the UNIX box
The MUA on the Linux box
What is different now from when it "worked in the past"

timinator · 11-17-2017, 01:59 PM

Sendmail on both boxes. Not sure what MUA is being used.

scasey · 11-17-2017, 04:12 PM

Quote:

Originally Posted by timinator

Sendmail on both boxes. Not sure what MUA is being used.

Sorry. I meant MTA, not MUA...fat fingers. Also, sorry, I don't speak sendmail...
You're sure that sendmail is running and listening?

timinator · 11-19-2017, 08:27 AM

[root@netmax2 ~]# sudo lsof -i :25
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
sendmail 1319 root 4u IPv4 17455 0t0 TCP netmax2.xxxsmotor.com:smtp (LISTEN)

bathory · 11-21-2017, 03:24 PM

Quote:

sendmail 1319 root 4u IPv4 17455 0t0 TCP netmax2.xxxsmotor.com:smtp (LISTEN)

Are you sure that netmax2.xxxsmotor.com resolves to 172.17.X.X?
According to your OP, the unix server is trying to connect to 172.17.X.X in order to relay mail

timinator · 11-21-2017, 03:38 PM

Got it to work in a weird way:

I commented out the following line in sendmail.cf on the Linux box

#O DaemonPortOptions=Port=smtp,Addr=127.0.0.1, Name=MTA

bathory · 11-21-2017, 05:02 PM

Quote:

Originally Posted by timinator

Got it to work in a weird way:

I commented out the following line in sendmail.cf on the Linux box

#O DaemonPortOptions=Port=smtp,Addr=127.0.0.1, Name=MTA

That means that sendmail was listening only on the local loopback interface and that 127.0.0.1 resolves to netmax2.xxxsmotor.com instead of localhost.

Just a FYI:
This is not the adequate way to change sendmail options.
You need to edit sendmail.mc and use either one of the following:

Code:

DAEMON_OPTIONS(`Port=smtp,Name=MTA’)dnl
dnl DAEMON_OPTIONS(`Port=smtp,Addr=127.0.0.1, Name=MTA')dnl

Then run the following command to create the new sendmail.cf (don't forget to make a backup of the old sendmail.cf):

Code:

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

After that, restart the sendmail service

Regards

PS: Mark the thread SOLVED

timinator · 11-22-2017, 07:17 AM

Thanks for the reply. Can you explain a couple of things?

What is "dnl"?

and what is "m4"?

Thanks

bathory · 11-22-2017, 07:40 AM

Quote:

Originally Posted by timinator

Thanks for the reply. Can you explain a couple of things?

What is "dnl"?

and what is "m4"?

Thanks

Everything is explained here