The mail app will open all by its self. After checking mail and then minimizing the app, it will suddenly just pop open again. There is no new mail in the inbox when this happens.
iMac with Retina 5K display, macOS 10.14
For anyone who did not see my solution/workaround from a while back in this thread, i'll link to it here https://discussions.apple.com/thread/250385204?answerId=251388086022#251388086022. It includes quite detailed instructions, but the basic idea is that two step authentication for gmail does not work properly in the Mail app. The workaround is to not use the built-in google preset when adding the account. Instead manually set it up (which is quite easy as well) with an "App password" set up in the google account. For me, this has worked for over two months without mail ever opening since.
That may work for a single non-business gmail account , but when you have multiple G-Suite accounts its not practical.
With your same Apple ID you can sign up for a free Developers Account and start a conversation with Apple engineers
by filing a Bug Report: https://bugreport.apple.com/
I have a fix for this.
In the dock, right clic and activate open at start.
Then in the user settings, start items select mail as hide.
Since I've done this the problem do not repeated a single time.
I tried this too. It does not work. Window still randomly pops up.
Save yourself a ton of time - just go buy Airmail - problem solved and its a FAR better app than mail ever will be. Outlook is an abomination. Been there, done that.
Look at the solution proposed by FanatiQS ( Link to this Post ) it partially solve the problem. I did it and now it is accettable.
Mail App Opens Randomly Mojave 10.14.5
