[Dovecot] changing INTERNALDATE or similar

[Karl Rudnick]

Looking at the IMAP4rev1 protocol (RFC 2060), we have the following
definition:

INTERNALDATE   The internal date of the message.
2.3.3.  Internal Date Message Attribute

   The internal date and time of the message on the server.  This is not
   the date and time in the [RFC-822] header, but rather a date and time
   which reflects when the message was received.  In the case of
   messages delivered via [SMTP], this SHOULD be the date and time of
   final delivery of the message as defined by [SMTP].  In the case of
   messages delivered by the IMAP4rev1 COPY command, this SHOULD be the
   internal date and time of the source message.  In the case of
   messages delivered by the IMAP4rev1 APPEND command, this SHOULD be
   the date and time as specified in the APPEND command description.
   All other cases are implementation defined.

How could any implementation of this protocol possibly use a file system 
time stamp to represent that important piece of meta-data,
no matter where the file lives? It seems totally reasonable that this is
what Outlook uses for the Received date (and I rarely defend Microsoft).

This seems like a real design flaw in the dovecot implementation. I am fairly
new to dovecot (and like many aspects of it over uw-imap), but having
to really be careful with my mail store's mtimes borders on the absurd.
I realize it is "implementation defined", but the intent of the definition
surely does not refer to file system time stamps. Any chance this can
be reconsidered? Is this an actual dovecot issue or a more general Maildir issue?

On Fri, 2008-07-18 at 02:00 -0700, dovecot-request at dovecot.org wrote:
> ------------------------------
> 
> Message: 4
> Date: Thu, 17 Jul 2008 23:12:55 +0300
> From: Timo Sirainen <tss at iki.fi>
> Subject: Re: [Dovecot] changing INTERNALDATE or similar
> To: richs at whidbey.net
> Cc: Dovecot Mailing List <dovecot at dovecot.org>
> Message-ID: <1216325575.31765.349.camel at hurina>
> Content-Type: text/plain; charset="utf-8"
> 
> On Thu, 2008-07-17 at 13:04 -0700, richs at whidbey.net wrote:
> > I believe it's still true that any mail files that are IMAP STORE'd
> > (uploaded)
> 
> You mean IMAP APPENDed.
> 
> > to Dovecot by a client will have a current mtime, rather than
> > the "Date" in the message.  That means might need to compare mtime's
> to
> > "Date" headers for new files that appear too.
> 
> This is only because the client doesn't specify the date to APPEND
> command.
> 
> > Here we just patched Dovecot to treat "INTERNALDATE" the same as the
> > "Date" header. Constantly verifying mtime's became too much of a
> chore
> > for those clients that rely on it (although this technically is
> against
> > the RFC).
> 
> Would probably have been better to set the default INTERNALDATE based
> on
> the Date: header in APPEND command. Should be pretty easy to do with
> Maildir I think.