I have been using mbsync+mutt for years successfully, managing a number of post boxes for accounts with different mailservers. Now there is reason for me (some business emails are so deep with html that not even lynx/w3c can display them near readable) and other people in my household (problems with mail fetching speed in gui clients with lots of messages) to want to create the following setup:
- sync mails via mbsync (or maybe offlineimap), sort them into a number of local maildir boxes (I have a working setup but may be willing to migrate)
- read/write mails from those boxes with mutt (I have a working setup for that)
- read/write mails from those boxes with some shiny gui-mailclient (-> just needs to be able to read maildir and support multiple senders on different servers)
- preferably thunderbird, though its maildir support seems to be fundamentally broken
- from my perspective: bonus points if the ui client is lightweight and QT :D
- if creating folders and moving messages into them from gui, then syncing that, is supported - brilliant!
I did some searching on the subject, though I could not find any suggestions that would lead to my goal. Specifically searching for mail clients that would use a local maildir managed by another service would not turn anything up, although I'm pretty sure that won't be something unreachable.
EDIT: mbsync is configured to retrieve mails from all accounts into ~/.imapmail/<account-folder>.