PMDF System Manager's Guide

VMS MAIL only hands over to PMDF those addresses that have the IN%"..." wrapper around them (or any synonyms for IN% you have defined on your system); VMS MAIL does not even tell PMDF about any purely VMS MAIL or DECnet MAIL or other foreign protocol addresses. PMDF of course can only construct headers showing the addresses VMS MAIL told PMDF about. Therefore if a VMS MAIL user sends a message to multiple recipients where some of the recipients are not handled via PMDF, then the recipients of the messages that went through PMDF will not see those other, non-PMDF recipients.

The only solution is to ensure that all addresses go through PMDF, by using the IN%"..." wrapper around all such addresses, or by using PMDF MAIL.