MBOX-Line: From tss at iki.fi  Sun Nov 20 08:22:30 2011
To: imap-protocol@u.washington.edu
From: Timo Sirainen <tss@iki.fi>
Date: Fri Jun  8 12:34:47 2018
Subject: [Imap-protocol] [noob] fetch envelope charset?
In-Reply-To: <F34CF1AC-E2DE-46C6-9B03-B8E71B993164@mac.com>
References: <F34CF1AC-E2DE-46C6-9B03-B8E71B993164@mac.com>
Message-ID: <C56F2770-30CD-477E-A534-0A615126B25B@iki.fi>

On 20.11.2011, at 16.48, Petite Abeille wrote:

> Given a fetch envelope command, what character set encoding can the response be in?
> 
> For example, say the subject is originally encoded as =?iso-8859-1?Q?H=F3la!?=, which is H?la! in UTF-8.
> 
> What can one put in the subject part of the envelope?
> 
> Does it have to be the original value (=?iso-8859-1?Q?H=F3la!?=)?

This is what all servers I know of do.

> Could it be the literal UTF-8 value (H?la!)?

Not without IMAP UTF8 extension enabled.

> Could it be the q-encoded UTF-8 value (=?UTF-8?Q?H=C3=83=C2=B3la!?=)?

I suppose it could be.

> Could it be the UTF-7 encoded  UTF-8 value (H+APM-la+ACE-)?

No.

> I'm really confused about what character set encoding IMAP is expecting and where. Is there perhaps a FAQ to complement the RFC that summarizes what applies where?

Mailbox names are mUTF7, SEARCH command has an optional CHARSET parameter, elsewhere there are no charset conversions.
