"I'll try" Wow, that was quite some "try" Kudo's!
This is important because the original ARPAnet NCP
used FTP to do mail
transfer.
If you look at RFC 765 (dated June 1980) , there are nearly a dozen
mail-related FTP commands. By RFC 959, it's successor five years later, all
of them were gone.
Another eary MTA was the MMDF, the Multichannel Memorandum Distribution
Facility, from U Delware. BBN ran it. One key point is that somehow when
used with MH you could get real-time address verification before sending,
"user rs(a)bbn.com doesn't exist." BBN ran MMDF for a long time because a
key
exec liked/needed that feature, long after 4.2 and sendmail. (My group was
one of the first to run sendmail, which I liked because of the "R$" lines
in its CF files. (Not really :) My Usenet/email gateway code had to
support MMDF but it was only ever used on
bbn.com)
could recognize ArpaNET address postfix and had a
hack in it, that
allowed the 'user' part of the address to include UUCP
addresses
Originally ihnp4!mirror!rs(a)seismo.arpa, then ihnp4!mirror!rs(a)seismo.css.gov
and then rs%mirror.uucp(a)seismo.css.gov and then rs(a)mirror.tmc.com Thanks
to Mary Ann and the "UUCP Mapping Project" for making much of that possible
and Peter Honeyman for Pathlias, and MX records for the last part. The
pre-MX styles received much scorn from Research, and if you search for
"that hideous name" you can find a paper on it. There's also a pathlias
paper, which Honey later said "was too good for Usenix" but he had nowhere
else to submit it.