Stresstesting IMAP clients (Hackvalue) [LWN.net]

Stresstesting IMAP clients (Hackvalue)

Posted Oct 6, 2009 11:10 UTC (Tue) by kelvin (guest, #6694)
In reply to: Stresstesting IMAP clients (Hackvalue) by dlang
Parent article: Stresstesting IMAP clients (Hackvalue)

> if nothing else, search for all messages with the 'new' flag and count them

Evolution used to use this method, but the problem is that deleted messages might still be flagged as "new". Combined with IMAP's braindead handling of deleted messages, this method causes discrepancies in the unread-count. There were bugs reported against these discrepancies.

Deleting messages in IMAP doesn't actually delete them, they are only flagged as deleted and you then have to manually "expunge" the folder. While this might have made sense to a computer-savvy user familiar with the mbox storage model, it is quite unintuitive to any user accustomed to modern GUI's (or MS Exchange/Outlook for that matter).

One solution might be for Evolution to "break" the IMAP spec by moving all deletion-flagged messages to the Trash-folder, including messages flagged by other mail agents. This would solve the problem for Evolution, and should be fairly non-disruptive for other mail agents.

Stresstesting IMAP clients (Hackvalue)

Posted Oct 6, 2009 22:37 UTC (Tue) by cortana (subscriber, #24596) [Link] (1 responses)

The hilarious thing is that since Evolution 2.26, these discrepancies have existed, even though Evolution does the stupid thing and treats IMAP like POP.

Day by day, I draw closer to the following conclusions:

1. IMAP is a horribly complex protocol
2. Because of 1, clients that implement the protocol correctly are non-existent
3. Because of 1, servers that implement the protocol correctly are rare

It's enough to drive one to gmail!

Stresstesting IMAP clients (Hackvalue)

Posted Oct 6, 2009 23:25 UTC (Tue) by dlang (guest, #313) [Link]

IMAP has lots of features, true

but it's not _that_ complex (web UIs are fare more complex, especially once you add AJAX), but it does require a very different mindset from pop clients to do well. the first thing that you have to accept is the idea that mailbox access is not exclusive and dedicated to one system.

once you start thinking that you may be accessing the same mailbox from your laptop, desktop, phone, etc _at the same time_ so that no one app has full control of the mailbox (the other apps may make changes that you are notified of) then you are most of the way there, and the rest of the decisions will probably be pretty good.

there are a couple of clients that work well with IMAP, and a couple of good servers. this isn't that different from other areas

how many good HTTP clients and HTTP servers are there? not that many (and on the client side, you could argue that most of the common ones in use are not among the short list of good ones ;-)

Stresstesting IMAP clients (Hackvalue)

Posted Oct 6, 2009 22:53 UTC (Tue) by foom (subscriber, #14868) [Link]

Ummm. So I have this mail program. Apple Mail. Guess what it does to delete messages? Flags them
as deleted. They stay in their mailboxes, hidden, unless you select "Show deleted messages"
from the menu. It works great, and is quite intuitive.

There is an option "Move deleted messages to Trash mailbox" if you want to copy Outlook-style
stupidity. Then it will actually move (well...copy; IMAP doesn't have a move command) the messages
to a separate Trash mailbox. A *REAL* Trash mailbox. I don't use that option, because I *like*
having my deleted messages segmented by origin mailbox (aka: the way IMAP was designed to
work), but it's there.

But neither of those options require that you download the entire header list just to be notified of
new mail. Only the method that Evolution decided upon has that requirement. And they call
it a feature! Crazy!