On 13 Feb 2021, Paul Hayton said the following...
 
 PH> do you have zip installed? It may look like it's zipping up a packet but
 PH> if there's no zip all you end up with is the BSO mailer file and no
 PH> packet to send

    Yes, I do have zip installed: I have even checked and the
/mystic/echomail/out/primary directory does have the .fr0 file there...
unzipped it with unzip and the .pkt file inside is also fine. 

--- Mystic BBS v1.12 A42 2019/02/01 (Windows/64)