[Dovecot] Getting the SMTP envelope through IMAP?

[Dennis Guhl]

On Fri, Oct 21, 2011 at 05:34:49PM +0200, Hadmut Danisch wrote:
> Hi,
> 
> just a simple question about dovecot:
> 
> The mbox file format contains the SMTP envelope sender and transmission
> date in a FROM ... line preceding the RFC822 mail header and body.

The line 'From foo at bar [..]' is only a seperation for different emails
in the mbox (in contrast, an RFC 822 From: is followed by a colon).

> As far as I see at the moment, the IMAP protocol does not support
> transmission of that SMTP envelope data in either way, but confusingly

The SMTP envelope does only exist within the involved MTAs and only as
long as the message is not finally delivered.

And if the MTA does not reveal the value of MAIL FROM: there will only
be the address from the Return-Path: or From: header fields to
populate the From line.

> uses the term „envelope” for a structure describing the RFC822 mail header.
> 
> My question is, whether there is any way to retrieve the SMTP envelope
> through dovecot's IMAP anyway, maybe through some extension.

Hardly. Even something like FETCH 1 (BODY[HEADER.FIELDS (FROM)]) would
not reveal the mbox message seperator but the RFC 822 From: header.

Dennis