Mailplane & macOS Sierra
Apple released macOS Sierra two days ago. You can read a bit about the new features here.
We’ve been running Mailplane 3 for almost two months on macOS Sierra and it works great. Make sure you’re on the latest version by going to
Mailplane 3 > Check for Updates... or downloading it here.
Attention: Mailplane 2 doesn’t run properly on macOS Sierra. All existing customers still get an upgrade discount of 20%. See also here.