fdm, imapsync, lots of similar alternatives. Synchronize email to your machine and then use any MUA, or even several of them, to read it from a local directory

fdm, imapsync, lots of similar alternatives. Synchronize email to your machine and then use any MUA, or even several of them, to read it from a local directory (Thunderbird also works AFAIK). They can also remove email from the remote and keep just the local copy. Pretty much 1:1 with POP. I've been using this setup (with fdm) for probably more than a decade.