MRC%PANDA@SUMEX-AIM.ARPA (Mark Crispin) (01/09/86)
Folks -
I am getting rather tired of explaining this over and over again,
when the Internet protocols are available for all to read (RFC's 821 and
822).
Please rest assured that I know what I am talking about. I was a
member of the committees that designed the Internet mail protocols, and
have been the developer of the mail system used on SU-SCORE (and other
TOPS-20's) for years.
There is no such thing as "Errors-To" in the Internet protocols. It
is a fantasy invented by certain Unix-based mailers to compensate for
deficiencies in Unix software and protocols. You can be quite confident
that "Errors-To" was generated by some Unix system.
The TOPS-20 mail system uses upper case for things such as host names.
In general, if you see something that has a lower case host name you can be
confident that it came from some Unix system.
The purpose of "Return-Path" is ***** NOT ***** to be the "true sender
of the message" which Mabry Tyson erroneously states. The "Return-Path" is
the path by which errors in delivering the message should take.
In other words, for once, the Unix mailers which are generating return
paths (which are not really in the header; they are outside in the "envelope")
are doing something quite correct and reasonable. By setting the return path
to be INFO-ATARI-REQUEST@SU-SCORE.ARPA they are stating that delivery error
notifications should be sent to the maintainer of the INFO-ATARI list.
-- Mark --
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