I recently had to change the IP address of my OpenVms 7.3 server to another range, and even though I thought I had changed the forewarding mail server properly (it's IP also changed), smtp mail is incredibly slow. It does eventually get there, but only after about 2 hours. The TCPIP$SMTP queue is constantly busy. Also, the external smtp server is on the same LAN, so it's not a routing or network problem

Lösung:

the key thing to note is that one must define both ZONE and ALTERNATE GATEWAY. I.e.

$ tcpip set conf smtp/zone=xxxx.xx/gate=alt=a.smtp.gate

All mail destined to the defined zone will be delivered \"locally\" using MX records etc.
All mail destined to domains outside \"our zone\" will just delivered straight away to the given gateway.

remember to do $TCPIP STOP MAIL check that TCPIP$SMPT... queues are stopped and restart stuff using $TCPIP START MAIL and before starting, it might be VERY USEFUL to do

$ define/system tcpip$smtp_log_level 3
so get more stuff to log files. One can also have more execution queues. Do

$ tcpip stop mail
$ tcpip set conf stmp/Queues=n
$ tcpip start mail

And check that you can actually reach the DNS servers.

$ tcpip show name
and test accessibility of the dns servers you are using