Path: utzoo!attcan!uunet!wuarchive!usc!ucsd!ucbvax!husc6!cmcl2!stealth.acf.nyu.edu!brnstnd
From: brnstnd@stealth.acf.nyu.edu
Newsgroups: comp.unix.questions
Subject: Re: Unix mail files.
Message-ID: <1163:May2719:09:5690@stealth.acf.nyu.edu>
Date: 27 May 90 19:09:56 GMT
References: <23447@adm.BRL.MIL>
Reply-To: brnstnd@stealth.acf.nyu.edu (Dan Bernstein)
Organization: IR
Lines: 19

In article <23447@adm.BRL.MIL> pg@cxa.daresbury.ac.uk (Paul Griffiths) writes:
>    Is there anyone out there who can tell me how individual messages
> in a mailbox (ie /usr/spool/mail/$USER) are seperated from each other.
>    The only distinguishable feature I can see is that each message begins
> with a line specifying who the message came from, ie
> 	From Info-unix-requests@uk.ac.nsfnet-relay
>    Note that the "From" has NO `:' following it. Am I on the right track ???

Yep, exactly right. You'll also note that if a line in the text of a
message starts with From and a space, the mailer adds a > to the line;
that way mailreaders won't think that it starts a new message.

To be precise, the separator is "\n\nFrom ".

There are other popular conventions for mail. The easiest to work with
has every message in a separate file; unfortunately, this also wastes
the most space.

---Dan