Ran in to QWK/QWKE problems on my BBS downloads so remembered files/fsx_utls/MMSRC051.ZIPMMSRC051.ZIP was a fix for such
issues. You'll find if you try to compile it, your missing
curses.h
If you use apt you need to do
sudo apt-get install libncurses5-dev, if your using
yum install ncurses-devel ncurses. Generally things are
compiled as root in /usr/local/src, so you become root (sudo -i)
cd /usr/local/src ; unzip -e /mystic/files/fsx_utls/MMSRC051.ZIP
while in /usr/local/src, it makes an mmail-0.51 directory. You
enter that and do 'make', it may show warnings but no
fatal errors, next 'make install' and mm (mmail) will
be installed.
Hmm, nice try but still got errors from my bad .qwk file ;(
Still I have multimail 0.51 installed now ;)

--- Mystic BBS v1.12 A39 2018/04/21 (Raspberry Pi/32)
* Origin: Mystic Pi BBS bcw142.zapto.org (21:1/145)