MBOX-Line: From Neil_Hunsperger at symantec.com  Wed Apr  8 15:29:51 2015
To: imap-protocol@u.washington.edu
From: Neil Hunsperger <Neil_Hunsperger@symantec.com>
Date: Fri Jun  8 12:34:54 2018
Subject: [Imap-protocol] SEARCH semantics
In-Reply-To: <c94a9300-489f-4fca-87e6-992ccc1221e8@gulbrandsen.priv.no>
References: <55246A71.27553.323D151D@David.Harris.pmail.gen.nz>
	<c94a9300-489f-4fca-87e6-992ccc1221e8@gulbrandsen.priv.no>
Message-ID: <14D026C7F297AD44AC82578DD818CDD038F0C37385@TUS1XCHEVSPIN35.SYMC.SYMANTEC.COM>

> From: Imap-protocol [mailto:imap-protocol-
> bounces@mailman13.u.washington.edu] On Behalf Of Arnt Gulbrandsen
> 
> David Harris writes:
> > 3: The following search is valid, according to the syntax in RFC3501:
> >
> >    xx SEARCH OR OR <exp1> <exp2> <exp3>
> >
> > and allows an OR expression to cover three terms instead of
> > just two. As such, it
> > seems quite useful, but it would certainly have mystified my
> > old search code (it was
> > rubbish, as I've pointed out), and I was wondering how
> > generally safe it would be to
> > use this type of expression?
> 
> I've seen this kind of thing many times, e.g. OR OR FROM x TO x CC x, and I
> think it's fairly widely used. IIRC the Symantec IMAP proxy uses nested ORs
> en masse.

Arnt, that's correct.

To answer David's question we had to balance the tree very carefully to avoid false negatives on some Microsoft Exchange Server versions.

-Neil