MBOX-Line: From ken at oceana.com  Wed Nov 23 19:21:10 2005
To: imap-protocol@u.washington.edu
From: Ken Murchison <ken@oceana.com>
Date: Fri Jun  8 12:34:36 2018
Subject: [Imap-protocol] IMAP capability for maximum APPEND message size?
In-Reply-To: <Pine.OSX.4.64.0511231556030.533@pangtzu.panda.com>
References: <Pine.OSX.4.64.0511231556030.533@pangtzu.panda.com>
Message-ID: <438531A6.1050000@oceana.com>

Mark Crispin wrote:
> I am considering the addition of a trivial new capability to IMAP that 
> would advertise the maximum size of a message in APPEND (and probably 
> also CATENATE).  This has the same purpose as the SIZE capability in SMTP.
> 
> Currently, the only message size limit in IMAP is 4294967295 (2^32 - 1) 
> due to IMAP's use of unsigned 32-bit integers.  Supporting that size is 
> troublesome due to +1 overflow problems.  Many implementations have much 
> smaller limits, such as both for administrative and technical reasons 
> (many filesystems encounter problems after 2^31 - 1).

Cyrus has a limit of somewhere around 102MB, just as a design decision 
(so I'm told).  I think an extension advertising the actual limit 
supported by the server would be useful.


> Rather than have this be a secret, I propose a capability called 
> MAXAPPENDSIZE=nnn, where nnn is the size.

Works for me.

-- 
Kenneth Murchison
Systems Programmer
Carnegie Mellon University

