Request for assistance
John Abreau
jabr at abreau.net
Tue Dec 17 22:08:09 EST 2002
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
Content-Type: text/plain; charset=us-ascii
Chris Meyer <cmeyer at MIT.EDU> writes:
> MAIL FROM: <youraddress at somewhere.net> [From: header, obviously]
> RCPT TO: <youraddress at somewhere.net> [To: line, obviously; note
> that you just type the address in both of the above as-is, no brackets
> or anything]
Those are indeed the correct SMTP commands, but your comments are
incorrect. This is the SMTP envelope, and it has absolutely nothing
to do with message headers. The message headers exist at the next
higher layer in the network stack above the smtp layer. The layers
are separate for a reason: in networking, "simple and robust" is the
polar opposite of "complicated and brittle". Mixing the levels by
turning the envelope addresses into the official header addresses
would be asking for trouble.
When sendmail accepts a message to deliver (i.e., when it didn't reject
the message), it will check for a number of required headers and try
to compensate for any that are missing. If "From" or "To" are missing,
sendmail will include the envelope addresses as "Apparently-From" and
"Apparently-To", respectively. The others that come immediately to
mind are "Message-id" (added if it's missing), "Date" (likewise),
"Sender" (if the envelope mail-from differs from the "From" header),
and "Received" (always added, to build an audit trail of the delivery
path).
- --
John Abreau / Executive Director, Boston Linux & Unix
Email jabr at blu.org / WWW http://www.abreau.net / PGP-Key-ID 0xD5C7B5D9
PGP-Key-Fingerprint 72 FB 39 4F 3C 3B D6 5B E0 C8 5A 6E F1 2C BE 99
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.0.7 (GNU/Linux)
Comment: Exmh version 2.5 07/13/2001
iQCVAwUBPf/mmVV9A5rVx7XZAQIIbgQA1HGaLs4Z92XUGMeMm+rKnopZskj46m5F
CLOudL+4w6buqst2ZENvparXkEyRD/pWDLW4JUaeFzznds8gpO7ce8I9sWobuBGz
p1qyQ9lagfI8V47rMMa45bURGINKw4LEhwgsU+DB1yqVRs+zU6AcObEGXYkuMvat
w4KRTnjXjT4=
=iYVA
-----END PGP SIGNATURE-----
More information about the Discuss
mailing list