- Michael M Slusarz slusarz@curecanti.org:
Quoting Patrick Ben Koetter p@state-of-mind.de:
we want to implement SPECIAL-USE in Thunderbird (TB), but we've run into problems. I believe you could help change that.
Here's the problem:
By default TB only lists subscribed (LSUB) folders when it accesses an IMAP server. However when I do a LSUB on recent Dovecot 2.1 code from mercurial I don't get to see the SPECIAL-USE flags. Therefore TB fails to identify which folders it should use and map to until someone tells it to list all folders (LIST) manually.
Central part of the SPECIAL-USE idea was/is to require as little user interaction as possible to automatically setup a MUA to do the right thing.
Speculating that probably most MUAs will do a LSUB by default and never will get to see SPECIAL-USE flags I think it is easier to have the server-side promote the flags.
Except you never, never, never, never, never can rely on LSUB for mailbox attributes. It says so right in RFC 3501 [6.3.9]:
The returned untagged LSUB response MAY contain different mailbox flags from a LIST untagged response. If this should happen, the flags in the untagged LIST are considered more authoritative.See also RFC 5258 [3.1], which discusses the difference between the base RFC 3501 LSUB command and the LIST-EXTENDED SUBSCRIBED option:
This option is intended to supplement the LSUB command. Of particular note are the mailbox attributes as returned by this option, compared with what is returned by LSUB. With the latter, the attributes returned may not reflect the actual attribute status on the mailbox name, and the \NoSelect attribute has a second special meaning (it indicates that this mailbox is not, itself, subscribed, but that it has descendant mailboxes that are). With the SUBSCRIBED selection option described here, the attributes are accurate and complete, and have no special meanings. "LSUB" and "LIST (SUBSCRIBED)" are, thus, not the same thing, and some servers must do significant extra work to respond to "LIST (SUBSCRIBED)". Because of this, clients SHOULD continue to use "LSUB" unless they specifically want the additional information offered by "LIST (SUBSCRIBED)".
Thanks for the clarification. I did some reading to get a better understanding. We'll probably stick with this and may go for LIST if the server does not announce LIST-EXTENTED:
t2 LIST "" "%" RETURN (SPECIAL-USE) p@rick
- LIST (\Sent) "." "AltSent"
- LIST () "." "Archives"
- LIST (\Archive) "." "AltArchive"
- LIST (\Junk) "." "AltJunk"
- LIST () "." "Junk"
- LIST (\Trash) "." "AltTrash"
- LIST (\Drafts) "." "AltDrafts"
- LIST () "." "Trash"
- LIST () "." "INBOX" t2 OK List completed.
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