Got any documentation for this API? $ help mail_routines It's also in the gray (or orange) wall, of course. Ideally I'd want to somehow "hook" into the MAIL application in the All I can say is that there's a documented path for doing this - there's \nothing special about SMTP in this regard. It's called a "foreign transport protocol" or something like that. You need to write a library with the appropriate entry points (this is where the documentation comes in handy), call it FIDO_MAILSHR, and install it. If you do the right stuff, VMSMAIL will recognize the FIDO%"..." address and call your library. Couldn't be easier :-) BOb