We use IMAP accounts exclusively. We access these account through email clients like Thunderbird and until now, the webmail client Squirrelmail.
Since installing Roundcube yesterday, I've noticed some problems immediately with IMAP usability.
issue 1: If the thunderbird client is open to the account (checks it every minute or two automatically) then roundcube will NOT self-update. I can get many mails and they won't show until either I refresh manually or if I close the thunderbird client. It appears that there is some kind of "last checked" flag in the IMAP protocol and Roundcube is making the very bad assumption that it's the only client checking the account. Obviously the expected behavior is the automatic updates work properly regardless if other IMAP clients are connected.
issue 2: Related to issue 1, if the thunderbird client deletes or moves a message, it throws RC into confusion. The message appears greyed out. manually refreshing won't fix it. Only after deleting a couple of messages (exactly 2 messages) will the client resync.
issue 3: related to the first two issues, obviously the auto update of RCM won't show changes when another client deletes or moves a message.
From my point of view, roundcube is making some design assumptions that it is the only active IMAP client connected to an account and all changes would be coming through the web interface. It's a bad assumption. The IMAP functionality is significantly hobbled.
