[CentOS] postfix relay and mail host for HPC cluster

Fri Jan 16 17:37:29 UTC 2009
Tony Schreiner <schreian at bc.edu>

I've so far been unable to make the following work:

I have a small cluster with a master node  ( called bayes.bc.edu on  
the public network, and called master.cl.bc.edu on the internal network). and a number of nodes which are purely on the  
private network.

I want the master to receive mail and deliver locally (or use .forward  
and alias rules) to messages sent from the nodes to user at master, and I  
want it to relay non-local addresses to my campus relay host which is  
another machine.

The relay part works ok,  all mail addressed in a form that my campus  
relay host recognizes gets delivered. The problem is that mail to

user at master.cl.bc.edu  (the internal name)  gets relayed to the campus  
relay which does not know about the host name master.cl.bc.edu because  
that is defined on a private DNS server for the cluster, and the  
campus relay rejects the message.

How can I get my cluster master to not relay messages addressed to  
The queueing/resource manager (torque/pbs) wants to send automatic  
status messages to user at master.cl.bc.edu and that cannot easily be  

Mail MTA is postfix for both master and nodes
Some postfix settings on the master.

myhostname = bayes.bc.edu
mydomain = bc.edu
myorigin = bayes.bc.edu
inet_interfaces = master, localhost
mynetworks =,
relayhost = mail.bc.edu

and some settings on the nodes

mydomain = cl.bc.edu
myorigin = bayes.bc.edu
inet_interfaces = localhost
relayhost = [master.cl.bc.edu]

Thanks for any help,
Tony Schreiner