On 9 Jul 2001, at 18:08, Norbert Bollow wrote:
> Can someone recommend a website (or other text) which explains
> everything that list-owners need to know about SMTP? (E.g. the
> difference of envelope sender and From: header, what happens in
> forwarding, how to read Received: headers.)
Well, One thing I can recommend/suggest is that you try reading the
actual specifications. The two key RFCs that govern all of this are RFCs
821 and 822. They've recently been revised [although the new ones aren't
official yet, are they?] as RFCs 2821 and 2822. They're all quite
readably-written [esp the new, revised versions], aren't all that long,
and I don't think they're all that hard to understand. NOTE: don't
bother too much, other than in spots where you're curious, with all the
BNF and grammar rules. Focus on all of the running expository text and
just sort out the grammar stuff when you need a detail [and even then it
is easy.
For example, I was recently wondering if the message-Id field in an email
message is required or not [I was pretty sure it was not, but I couldn't
remember for-sure]. so I hopped over to RFC 822 and easily found:
optional-field =
/ "Message-ID" ":" msg-id
/ "Resent-Message-ID" ":" msg-id
/ "In-Reply-To" ":" *(phrase / msg-id)
/ "References" ":" *(phrase / msg-id)
/ "Keywords" ":" #phrase
/ "Subject" ":" *text
[...]
and even if you're not a real grammar-whiz, it is pretty clear [i think]
that "Message-ID" is one of the "optional-field"s. [as is 'Subject,
although many folk don't know that].
821/2821 is the SMTP spec. It is the machinery that moves mail from one
place to another and is the definition of the 'envelope' machinery. As
you will see, it uses *NOTHING* of the 'letter' [822] content of the
message for its handling.
822/2822 is the Mail-format spec. It defines what's what with the letter
that goes _in_ the envelope.
For another example, you mentioned the 'Received' field.. since that's
part of the message, again you go to 822 and you again easily find:
4.3.2. RECEIVED
A copy of this field is added by each transport service that
relays the message. The information in the field can be quite
useful for tracing transport problems.
The names of the sending and receiving hosts and time-of-
receipt may be specified. ....
Anyhow, I'm sure there are books and such that talk about this stuff, but
I've always found it most direct and best just to go to the 'horse's
mouth' for 821/822...
/bernie\
/Bernie\
--
Bernie Cosell Fantasy Farm Fibers
mailto:[EMAIL PROTECTED] Pearisburg, VA
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