Sendmail and Scalix SMTP Relay Question

[jpkovacic]

Our current Scalix 10 setup involves the Scalix SMTP Relay listening on external port 25 while Sendmail listens on port 25 on localhost (127.0.0.1). Our system admin has expressed a desire to reverse this: having Sendmail listen on external port 25 while the Scalix SMTP Relay listens on port 25 of localhost. Can this be performed? Will this setup hamper or break the Scalix system? If it can be performed, does Scalix have a recommended procedure for performing this task?

We currently perform a cold backup of our mailstore each evening. Since we have to shut down the Scalix system to perform the cold backup, we have no process listening on external port 25 to queue up incoming mail. We figure that if we can get Sendmail to listen on external port 25, we can have it queue up incoming mail while the cold backup occurs.

BTW, we tried the LVM setup numerous times and it proved disasterous (i.e., we had to reinstall the RedHat Enterprise Linux ES V4 OS each time). This is why we are performing cold backups.

Thanks,
Joe K

[ScalixSupport]

The purpose of having sendmail listening on localhost:25 is for outgoing mail. If you put the SMTP relay on that address, you'll get a routing loop.

It would be good to know what your admin is looking to achieve as there may be ways to do this already in Scalix.

If you've looked through the SpamAssassin technote, you'll see that there is a setting in smtpd.cfg ( SMTPFILTER=TRUE ) which will force all incoming mail, destined for a Scalix address, through sendmail first.

Cheers

Dave

[jpkovacic]

The main reason we were looking for the port 25 listening swap involved the Scalix mailstore cold backup. Is there any way to queue up incoming mail while the Scalix services are shutdown during a cold mailstore backup? Do we have to shutdown the Scalix SMTP Relay during a cold backup?

Thanks,
Joe K

[ScalixSupport]

If you're doing a cold backup, Scalix should be shut down anyway but it sounds like you are only shutting down a few of the services.

To answer the question, yes. Shut down the SMTP Relay and let the sending MTAs queue the mail as they should.

Cheers

Dave

[jpkovacic]

I'm a little confused. With all of the Scalix services shutdown, is there anything listening for incoming mail during the cold backup? Are these incoming messages being bounced back to the source during the cold backup?

-Joe K

[ScalixSupport]

SMTP Relay is not listed as a service, you need to run

Code: Select all

omstat -a

to see its status but you can still run

Code: Select all

omoff -d0 smtpd

to shut it down and

Code: Select all

omon smtpd

to start it back up again.

If that is shut down, the sending side is supposed to queue the messages until the connection is available again.

Cheers

Dave

[jpkovacic]

Thanks for your help. I've already relayed your info to our systems admin.

-Joe K