Running into all sorts of problems with 'Mail app' and now 'Gmail app' using a third-party imap server. Lots of message with an HTML body or attachements are di

Running into all sorts of problems with 'Mail app' and now 'Gmail app' using a third-party imap server. Lots of message with an HTML body or attachements are displayed blank. Google really, really wants you to use GMail, so the development effort they put into supporting other email setups is of the "just enough to make the sale" variety. My solution to this specific AOSP issue is to use K9 Mail which (in my experience) is far better than the stock Android Mail app. (It was forked from the AOSP Mail app some years ago IIRC & has an active development community & github repo.) I don't have any solutions to your other (perfectly reasonable) complaints unfortunately.