MBOX-Line: From tss at iki.fi  Wed Mar 27 03:27:31 2013
To: imap-protocol@u.washington.edu
From: Timo Sirainen <tss@iki.fi>
Date: Fri Jun  8 12:34:50 2018
Subject: [Imap-protocol] Working around the evils of LITERAL+
In-Reply-To: <B2E07E1B-80E9-4FFB-8518-B4CDC344639E@isode.com>
References: <CABa8R6s3rK5JkXBtV7RWbav9T2GBCg+pw-aWd9=5Szv3ocDS_g@mail.gmail.com>
	<DA4AB101-1D7E-466C-8DA1-6234EB098FF8@iki.fi>
	<CABa8R6v5dApFF6Quwzrb0=XethrwCU0EQT6t3XtLVK6VRoYhmA@mail.gmail.com>
	<B2E07E1B-80E9-4FFB-8518-B4CDC344639E@isode.com>
Message-ID: <78AB33AC-4EFC-42AF-80F8-AD1FB3C26746@iki.fi>

On 27.3.2013, at 12.03, Alexey Melnikov <alexey.melnikov@isode.com> wrote:

>> And that limit is advertised via EHLO at SMTP time, but there's no mechanism for doing that with IMAP.
> 
> Let's standardize a way to advertise such limit. I might have use for it as well.

I wonder if it should be per-mailbox limit.. Something like:

a LOGIN foo bar
* OK [APPENDSIZE 10000000] Maximum size allowed by this server
a OK Logged in
b SELECT INBOX
..
* OK [APPENDSIZE 10000] Maximum size allowed by this mailbox.
..
c UNSELECT
c OK
d APPEND elsewhere {100000}
d NO [APPENDSIZE 1000] Too big message
d APPEND elsewhere {100000+}
d NO [APPENDSIZE 1000] Too big message

Although using the same APPENDSIZE may confuse clients. Then again using different GLOBALAPPENDSIZE and MAILBOXAPPENDSIZE may cause clients to use only one of them.

So .. maybe a per-mailbox limit isn't that useful. I was mainly thinking about different users having different limits, causing shared mailboxes to have different limits. Or maybe some other special mailboxes with special rules.

BTW. Another related issue is that IMAP is now limited to 4 GB mails. This RFC might as well allow servers and clients to increase that to 64bit value.
