Seems it is now almost a decade since I migrated from Thunderbird to GNUS. And GNUS is an awesome mail program that I still rather like. However GNUS is also heavily quirky. It's essentially single-threaded and synchronous which means you either have to wait for the "IMAP check for new mails" to finish or you have to C-g abort it if you want the user interface to work; You have to wait for the "Move mail" to complete (which can take a while -- especially with dovecot-antispam training the filter) before you can continue working. It has it's funny way around TLS and certificate validation. And it seems to hang from time to time until it is C-g interrupted.
So when I set up my new desktop machine I decided to try something else. My first try was claws-mail which seems OK but totally fails in the asynchronous area. While the GUI stays reactive, all actions that require IMAP interactions become incredibly slow when a background IMAP refresh is running. I do have quite some mailboxes and waiting the 5+ minutes after opening claws or whenever it decides to do a refresh is just to much.
Now my last try has been Kmail -- also driven by the idea of having a
more integrated setup with CalDAV and CardDAV around and similar
goodies. And Kmail really compares nicely to claws in many ways. After
all, I can use it while it's doing its things in the
background. However the KDE folks seem to have dropped all support for
the \recent IMAP flag which I heavily rely on. I do -- after all --
keep a GNUS like workflow where all unread mail (ref \seen) needs to
still be acted upon which means there can easily be quite a few unread
messages when I'm busy at the moment and just having a quick look at
the new (ref \recent) mail to see if there's something super-urgent is
essential.
So I'm now looking for useful suggestions for a mail program (ideally with desktop integration) with the following essential features:
- It stays usable at all times -- which means smarter queuing than claws -- so foreground actions are not delayed by any background task the mail program might be up to and tasks like moving mail are handled in the background.
- Decent support for filtering. Apart from some basic stuff I need
shortcut filtering for
\recentmail. - Option to hide
\seenmail (and ideally hide all folders that only contain\seenmail). Hopefully toggle-able by some hotkey. "Age in days" would be an acceptable approximation, but Kmail doesn't seem to allow that in search (it's available as a filter though).