MBOX-Line: From MRC at CAC.Washington.EDU  Thu Mar  8 16:10:00 2007
To: imap-protocol@u.washington.edu
From: Mark Crispin <MRC@CAC.Washington.EDU>
Date: Fri Jun  8 12:34:38 2018
Subject: [Imap-protocol] question on BODY[n.MIME]? 
In-Reply-To: <Pine.BSO.4.64.0703081647110.2904@vanye.mho.net>
References: <07Mar8.112542pst."57996"@synergy1.parc.xerox.com>
	<alpine.OSX.0.83.0703081129120.11046@pangtzu.panda.com>
	<07Mar8.141232pst."57996"@synergy1.parc.xerox.com>
	<alpine.WNT.0.83.0703081500000.4212@Tomobiki-Cho.CAC.Washington.EDU>
	<Pine.BSO.4.64.0703081647110.2904@vanye.mho.net>
Message-ID: <alpine.WNT.0.83.0703081607250.4212@Tomobiki-Cho.CAC.Washington.EDU>

On Thu, 8 Mar 2007, Philip Guenther wrote:
> Note that there's a difference between omitting a trailing field and 
> returning it as NIL: in the latter case, the client knows that the associated 
> header field isn't present.  If the server leaves it off entirely then the 
> client doesn't know whether the field exists or not and will have to do a 
> direct fetch of the missing fields if it's interested in them.

Good point.  I remembered that there was a reason why the server should 
send NIL instead of omitting, but I had a brain fart and forgot.

So, let me amend my previous statement: your server SHOULD process 
extension fields and SHOULD send NIL in the BODYSTRUCTURE if the fields 
are absent in the MIME-IMB header.  It SHOULD NOT omit them; that behavior 
is for legacy servers which do not implement the extension fields.

-- Mark --

http://staff.washington.edu/mrc
Science does not emerge from voting, party politics, or public debate.
Si vis pacem, para bellum.

