Say I wanted to post a text file to a particular forum on Mystic BBS.
Such a weekly ad, to the appropriate forums for them.

Check out mutil and mutil.ini. It has the ability to post a text file into a message base.

--- Mystic BBS v1.10 A51 (Linux)
* Origin: The Shadow Dominion BBS (46:3/102)
þ Synchronet þ thePharcyde_ >> telnet://bbs.pharcyde.org (Wisconsin)

How would you do something like that in Mystic?

Use the menu command to post a text file, or use MPL, or use the MUTIL
function to post text files. Mystic will also automatically split up large files into multiple messages too.

--- Mystic BBS v1.10 A52 (Windows)
* Origin: Sector 7 [Mystic BBS WHQ] (46:1/127)
þ Synchronet þ thePharcyde_ >> telnet://bbs.pharcyde.org (Wisconsin)