It seems the last release’s changes to strictly check domains on SSL certs broke gmail compatibility when you host your domain there.  There is now a Mac beta of 2.3 with this fix available. The version number has increased because this is also the first release running in  the MacOS hardened runtime.  Let me know if you see any oddities. It’s an added layer of security  for users that I would like to take advantage of.  This is the first beta trying it out but going forward Monal builds not in the App Store will also be notarized.