We are currently considering zammad as our ticket handling platform. We are very impressed with nearly all aspects of your product. There is only one thing that keeps us from going all in and that is how to setup gmail/google inboxes.
For the moment this requires user/password login and “allow less secure apps” to be enabled on your gmail inbox, but we would rather use the recommended OAuth mechanism as suggested by Google. Mostly because Google is retiring this mechanism in the foreseeable future.
If found a recent github ticket in your repository that mentions a git branch. Could you shed a light on how far developed this is, and when we could see this functionality in a release?