Re: Breaking mailutils to pieces

[Sam Roberts]

Quoting Harald Meland <address@hidden>, who wrote:
> [Sam Roberts]
> 
> > 6- Find a way to store "envelope to" in a mailbox.
> > 
> > Envelope from is in the mbox format, I don't know about the
> > other mailbox types, but if anybody knows what the common ways
> > that MDA's put this info in, when they do, maybe we could use
> > that. I'm thinking of an X-Envelope-[From|To] field, that
> > the evelope_t would understand.
> 
> Exim (optionally) adds an "Envelope-to:" header to mails at delivery
> time, containing the envelope to address that resulted in that mail
> delivery.

Looking through my mailboxes, it looks as if fetchmail is also doing
this when after it pulls mail from my pop server, and before it
pushes into sendmail for local delivery.

> > Also, does it remove the BCC lines? I guess that sendmail does
> > when used as the messeage injection interface (i.e. if you
> > send a message to it's stdin, it will make sure the message has
> > a message ID, a date, stip the bcc and add those addresses to the
> > envelope to, etc). I'm not so sure that when you talk to an MTA
> > using smtp that it will do this.
> 
> MTA dependant; Exim will *not* strip Bcc: headers when receiving mail
> via SMTP (and I believe that is fully RFC compliant).

I believe it is compliant as well. There's a little confusion, it
appears to me, since SMTP seems to be used as a mail submission protocol
(right word?) as well as a mail transfer protocol.

Does anybody have pointers to documentation of how /bin/mail
(when used for local delivery, as I've heard rumours it is) or
/bin/sendmail is used?

It appears to me that they:
 - read the message from stdin
 - canonicalize the line endings
 - put a date: header, if not present
 - put a message-id: header, if not present
 - what about uid or uidl? Is that done when a pop or imap server
   reads the box?
 - strip bcc fields
 - perhaps parse to,cc,bcc for addresses to deliver the message to
 - perhaps only accept addresses on the command line, and then
   leave the headers untouched?

Also, does anybody have a copy of "Sendmail: theory and practice"
by Avolio and Vixie, a blurb I read on it said:

  This book emphasizes how sendmail fits into the mail system
  in general more than the deep details.

Which would be good, since I don't want to be able to read a
sendmail configuration file, but I do want to know what sendmail
does, since that seems to define "common practice".

Recommendations?

Sam

-- 
Sam Roberts <address@hidden> (Vivez sans temps mort!)