[Dovecot] Deleting a folder with & character

[Timo Sirainen]

On 19.9.2012, at 13.36, Charles Marcus wrote:

> On 2012-09-19 5:14 AM, Timo Sirainen <tss at iki.fi> wrote:
>> It's an invalid mailbox name and you can't access it using doveadm. Either rename it with "mv" or via IMAP protocol (not entirely sure if it works via IMAP either). 
> 
> Just for clarification... it is invalid because of the '&' character? Is there a list of dovecot (or is this simply the IMAP protocol in general?) considers invalid characters in folder names somewhere?

mUTF7 uses the & character for encoding non-ASCII data. The & character is encoded in mUTF7 as "&-". Dovecot nowadays uses UTF8 internally for all mailbox names, and it's simply not possible to create from UTF8 string a valid mUTF7 string that contains & alone.

Dovecot has also some additional restrictions on characters (mainly control chars), but they are only enforced when creating new mailboxes. Opening existing mailboxes with control chars is allowed.