The state of MUAs isn't bad/sad unless you apply a pile of unreasonable constraints, as you have. Then, yeah, you can't find anything. Loosen up. "Written in C" is an issue for you? And you use Linux? Just give Evolution another try and give it a little time.
I find your answer a bit intrusive, to be honest. Let's just stick to the subject matter instead of telling each other how unreasonable or uptight we are, okay?
Yes, "written in C" is an issue for me, for two reasons:
* I really do want to do rapid prototyping and testing hypotheses regarding MUA UX, and C is just not suitable for this end.
* I keep reading about security vulnerabilities in common mail software caused by (among others) buffer overflows.
I don't think that MUAs benefit from C the way system software (such as the kernel) does. And compared to MUAs that run in the browser, I think that the bloat introduced by using Go or Python is still justifiable. Fortunately, there already exists a MUA written in Go (namely aerc).
