Client issues and configuration
It seems to be quite difficult to implement a working IMAP client. Best Practices for Implementing an IMAP Client tries to help you with it.
On Mac OS X Leopard 10.5 Mail.app appears to support subscribe/unsubscribe by right clicking on a mailbox, selecting 'Get Account Info' and selecting 'Subscription List' from tabs. This however doesn't really work with any IMAP server.
Apple Mail 3.6 (that comes with OS X 10.5 Leopard) supports subscribing/unsubscribing to folders in the public namespace.
You should enable outlook-no-nuls workaround with POP3.
Outlook 2003 has problems with older Dovecot's default POP3 UIDL format, which causes it to download the same mails over and over again if "leave mails to server" option is enabled. See pop3_uidl_format setting.
Outlook might not hide or purge deleted items by default. Microsoft has a how-to that shows how to fix this (Outlook 2007, not Outlook 2003).
- If some Outlook users don't see new or sent mails in the appropriate folders after a migration from UW IMAPd even if they are visible in other clients (e.g. Roundcube, Thunderbird, or on the disk itself), and you get the error message "BAD Error in IMAP command UID: Invalid UID messageset" in the log or rawlog: It helps to remove the problematic IMAP account completely from Outlook and recreating it again there. It speaks a different IMAP afterwards, so there are reasons to believe it caches the details of some server on the first connect and doesn't refresh them even if you change the server's hostname in the account settings.
Outlook Express 6
- Using "Headers only" synchronization is buggy and can cause "Message is no longer available on this server" error when opening a mail. This isn't Dovecot specific problem, and I'm not aware of any possible workarounds at the moment for this in server side.
You should enable delay-newmail workarounds for IMAP.
You should enable outlook-no-nuls and oe-ns-eoh workarounds for POP3.
I'm not actually sure what version exactly this refers to.
You should enable oe-ns-eoh workaround for POP3.
- Some versions don't support creating subfolders with mbox format. Evolution in Ubuntu Gutsy, 2.12.0-0ubuntu5, does support creating subfolders, at least when the parent folder is empty.
Seems to be OK.
You should enable tb-extra-mailbox-sep workaround for IMAP. Bug report.
If you're using mbox:
Versions of Thunderbird from at least 17 (possibly earlier) up to 24.0 display incorrect new mail counts in the New Mail notification box. This is due to a bug in Thunderbird's handling of the CONDSTORE extension. See Bug Report for details and a client-side workaround.
- New mutt versions supporting IDLE command will hang with Dovecot versions earlier than v1.0beta3. Upgrade Dovecot or disable IDLE by setting imap_idle=no in .muttrc.
Seems to be OK.
Configuration asks IMAP server name for some workarounds. There has been a Dovecot option since 1.4.6 and 1.5.1. For older SquirrelMail versions, select the "other" option and remove the default INBOX-prefix.
Dovecot namespace detection works automatically with any recent version of IMP (4.1+).
Quota support is now integrated into the 'imap' driver (as of horde-groupware V1.2), an example config of /imp/config/servers.php is:
$servers['imap'] = array( 'name' => 'IMAP Server', 'server' => 'localhost', 'hordeauth' => false, 'protocol' => 'imap/notls', 'port' => 143, 'quota' => array('driver'=>'imap'), );
Uses the namespace returned via Dovecot, full support via IMAP/POP3 using @Mail. Can also read mailbox quota via the getquotaroot IMAP command.