This is a seemingly simple problem. I want to access my gmail mail account using some other client than googles web interface. Sounds easy right? Gmail supports IMAP so any email client should work.
Except none of all I've tried (Thunderbird, gnus, Wanderlust, ...) can handle the huge amount of mails I got. Workarounds such as deleting or archiving mails to keep the mailboxes small doesn't count as a solution. Gmail doesn't require me to do that so I shouldn't have to do that with another client either.
For example, I got a mailbox of python-list with ~900k mail which Gmail's web interface opens in less than 3 seconds. All other clients I've tried just chugs on it for minutes. Someone must have had the same problem as me and solved it somehow?
Edit: I'd like to state that there is an answer to the question, and the answer is that there is no such program. The gmail web client and android app uses a completely different interface than IMAP which is much better suited for handling large amounts of mails. It may also be undocumented and proprietary extensions to IMAP, but the effect is the same: no client other than GMail's own can work as fast as it does.
So there annoying question closers; the question had an objective valid answer.