[Imap-protocol] MUTF7, UTF8, and Unicode flags

Jan Kundrát jkt at flaska.net
Thu Feb 20 09:53:21 PST 2014

On Thursday, 20 February 2014 18:10:01 CEST, Arnt Gulbrandsen wrote:

> just use UTF8 for mailbox names

Seriously? This is going to break stuff. You might argue that people
creating mailboxes named "&U,BTFw-" are unlikely :), but it's a valid
string both in UTF-8 and in the modified UTF-7 encoding -- except that the
two meanings are very different.

Implementing imap-utf7 is not hard, and chances are that there are
libraries which one can easily use in almost every language. Sending UTF-8
where the standard is absolutely clear on what to do is just wrong.

As for the flags/keywords, there's unfortunately no standard for that.
Thunerbird is using modified UTF-7 for them [1]. There's a proposal [2] for
using the METADATA extension for mapping ASCII keywords to Unicode names,
but I don't think it was ever standardized (and perhaps not implemented,


[1] https://bugzilla.mozilla.org/show_bug.cgi?id=650623

Trojitá, a fast Qt IMAP e-mail client -- http://trojita.flaska.net/

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