BSD 4.2 Mail not RFC822-compliant?

[Guy Harris]

>The AT&T salesperson pushed mailx really hard as a clean rewrite of berkeley
>Mail, but our copy (SysV on a Vax 11/780) dumped core randomly and frequently.
>Perhaps they've come out with something since that works?

Calling "mailx" a "rewrite" of "Mail" is incorrect.  The S5R2 "mailx" is
basically an *enhanced* version of a "Mail" of somewhere between 4.1BSD
and 4.2BSD vintage; the stuff they added is obviously new, but the
4.xBSD-derived stuff is pretty much unchanged.  The S5R3 one may have
changed more, but I still wouldn't call it a "rewrite".

>>It is interesting to
>>note that Sun's /usr/ucb/Mail is actually mailx.
>
>With how much work done by Sun??  At least the network stuff must
>have been added by Sun -- AT&T has only recently acknowledged the
>existance of SMTP mail.

Basically, stuff from the 4.2BSD (and, later, 4.3BSD) "Mail" was merged
back into the S5R2 "mailx" to make the SunOS "Mail".  Among the stuff
merged back was the use of "sendmail" to actually deliver mail, hence
the support for SMTP or anything else you get "sendmail" to support.  A
bunch of other miscellaneous stuff was added as well.