Adding to the earlier message in this thread you can't set the reply-to value in the multinet menu-drrven config tool
$ MULTINET CONFIGURE /MENU
...or command line. Further, you can't insert a line that sets the reply to value in systartup_v5.com because MULTINET_SMTP_REPLY_TO is set after login.
I edited the SYSTEM user's login.com (each user has their own) to include the DEFINE statement to set MULTINET_SMTP_REPLY_TO for SYSTEM, and proceeded to do this in a regular user's account.
This means that if you want to protect the gateway from being hijacked, EVERY USER needs to have an alias created on the gateway mail server I am using (buzz1.com) that forwards mail to its corresponding microvax 3100 user. The buzz1.com mail user will be DEFINE'd in at the user level's login.com
next I could set up a pattern for a lexical function such as for example
F$GETJPI(0, "USERNAME") to come up with a single logical name definition that
will work correctly for any user on the system without modification *assuming the gateway pair email alias uses same format*. i.e. email@example.com --> firstname.lastname@example.org