Mail failures since upgrading to Sierra - how do I uninstall Mail??

Mail consistently fails for me since upgrading to Sierra. I originally posted the problem at this link, and received a few tips - tried them all with no effect.

Re: Mail unusable since upgrade to Sierra

To net it out, SOME (not all) folders associated with one of my Gmail accounts will cause mail to crash when I try to access them. I've tried all the typical remedies (DB rebuild, DB reindex, remove and add account, re-install Sierra) with no luck. Today I tried a scorched-earth tactic: rooting out every mail-related file and folder I could find, then re-installing Sierra. Nope, must have missed something! It's not nearly as easy as deleting the library/mail folder; there are caches, plists, and likely other pieces of information that seem to live on even with an OS reinstall. Some bad file lives on from install to install and I can't find it. Does anyone have a definitive list of artifacts that must be deleted to get Mail to a "fresh" state?

Or - is there any way to have the failure logs analyzed?

This is super-frustrating. From time to time even having mail appear in the inbox will cause Mail to crash and I have to access Gmail directly from the web to clean it out before I can get Mail working again. Well, it still isn't working because I can't click on my folders!

ps - anyone have recommendations for some other mail app that can manage multiple accounts from various providers?