At $WORK, I have been slowly introducing my team to the git email workflow. Sending is working great, it was a bit painful to set up, but it is a lot less confusing then having to create a fork, branch out, etc.
However reviewing patches is a different story. The existing tooling is very much built for those who live in terminals (or Emacs). I wanted a tool that I could introduce to my teammates that would make it easy for them to get started with git patches. So I tasked an AI to create a plugin for Thunderbird. It introduces a patch button the user can click on.
Clicking it, users will find a familiar review interface.
It also has Sourcehut integration, so if it detects that the email is part of a Sourcehut mailing list, you can optionally also set the status of the patch.
I really think the issue with the email workflow is not so much the workflow itself but rather the tooling around it.
The source code is published for free. I've yet to publish the plugin in the addon manager, but for now it is quite straight forward to install it from source. There is a README with instructions.