There are a few requests to be able to sort messages by date, subject, and sender.
This would probably require us to implement Make Threading/Conversation View Optional first. However, Gmail does allow sorting threads by date of most recent message; other clients allow sorting threads by original subject or original sender.
(Original issues had 14 votes in total.)
Installed Mailspring today, and will have to uninstall, Iām afraid. 
No way to sort inbox is a dealbreaker for me. Especially being unable to sort by date, so now I see emails in reverse order. Itās the only email client Iāve seen that canāt sort inbox, and itās kind of baffling. I upvoted this request, but from the look of things this wonāt be implemented anytime soon. Sorry, I really wanted to love it.
Same here. Iām looking for a new client to replace Postbox or Thunderbird, and Mailspring has the most promise so far. But missing basic sorting is a real head-scratcher. I wonāt be able to use it on a daily basis without that.
Iām looking for this feature too. Unless Iām expecting something urgent in my inbox, I really like to have my list sorted by date from oldest to newest.
Appleās Mail.app allows threading and sorting independently. Threading is a grouping feature where the most recent message is used for sorting parameters (at least with respect to dates, and sender, I believe). If messages are sorted by flag (star) and threading mode is enabled, then if any of the threadās messages is flagged, the thread is treated as flagged. Itās actually really, really useful.
In other words (at least as best I can tell), threading is used to group messages and then sorting applies to the group as if it were a single pseudo-message (with varying behaviors regarding what comprises that pseudo-message from its members)
I need to have sort options for the inbox and folders.
Have created a PR with support for this request, no message/thread optional (though I think this should be implemented)