I haven’t used Mimestream, but I think the idea is that it’s built to use Gmail’s native API, which is more functional and well-behaved than Gmail’s IMAP implementation.
This allows it to function similarly to the Gmail web app while also being a good citizen of the Mac desktop and being much more lightweight.
I was a religious user of Airmail until it went subscription, Mimestream seems almost as good. It feels incredibly lightweight, it uses almost no RAM, and it has that 'cool' mac app polish.
A lot of the unexpected odd integrations of Gmail and an IMAP email client disappear, most notably including Search, which has never seemed to work quite right in Apple Mail w/ Google services.
I should of course just bail on Google, especially since they're discontinuing my previous freebie G-Suite account, but, well, you know.
