MBOX-Line: From janssen at parc.com  Sun Jun 22 13:29:11 2008
To: imap-protocol@u.washington.edu
From: Bill Janssen <janssen@parc.com>
Date: Fri Jun  8 12:34:42 2018
Subject: [Imap-protocol] '+' in counted literal (e.g. {548+}) -- where from?
Message-ID: <08Jun22.132913pdt."58698"@synergy1.parc.xerox.com>

I find that the Apple Mail tool (version 3.3) is sending my UpLib IMAP
server counted literals with an odd count.  The "number" part of the
count ends with a "+", as in "{548+}".  I don't know what that means,
or what IMAP extension defines that syntax...

My server advertises LITERAL+, NAMESPACE, UIDPLUS, IDLE.  RFC 4466
(Collected Extensions to IMAP4 ABNF) says,

   literal8        = "~{" number ["+"] "}" CRLF *OCTET
                      ;; A string that might contain NULs.
                      ;; <number> represents the number of OCTETs
                      ;; in the response string.
                      ;; The "+" is only allowed when both LITERAL+ and
                      ;; BINARY extensions are supported by the server.

It says that the "literal8" syntax was taken from RFC 3516, but
neither the character "+" nor the string "plus" occurs in RFC 3516, so
I don't trust either the spec or the attribution in RFC 4466.  My server
in any case doesn't advertise BINARY, and there's no "~" in the count
being sent by Apple Mail.

Any ideas?

Bill

