The mail server resides at a 172.16.0 net and the client machines at a
192.168.2.0 net. If I have understood the documentation correctly,
vpopmail must be configured with "--enable-roaming-users" if the
client machines are on a different net. Correct?
If you have clients at static IP's like 192.168.2.0 network then
use the RELAYCLIENT entry like below.
The entry in /home/vpopmail/etc/tcp.smtp is
172.16.0.:allow,RELAYCLIENT="" and I have done
Maybe I'm missing something too but shouldn't the contents of the
tcp.smtp file say:
since the connections are coming FROM the 192 network?
This is what you want, the client IP addresses.