Mesa is just a separate package. Especially if you are running Amd drivers that are part of the Linux kernel, it can be a good idea to use a more modern mesa package.
There is a PPA for that, that also works under Linux mint cinnamon edition: https://launchpad.net/~kisak/+archive/ubuntu/kisak-mesa





At this point I’m thinking of creating my own client haha.
I believe MailSpring is really powerful. But some advanced features are behind a pro account. MailSpring itself is open source.