I just got attachment deletion working over IMAP in mutt. After mucking around writing my own code to fetch a message and reupload it, I had a revelation and got it working in about 5 lines of code. This happens more and more often with the IMAP code base, which indicates to me it's coming together (although I still hate large parts of it, none more than the browser). Incremental improvements are probably better since they help you avoid making new mistakes while fixing the old ones, but I still get the urge to chuck entire source files sometimes. I'm mostly held in check by the fact that most rewrites I'd like to do would involve significant changes in mutt core (which isn't really designed with modules in mind).