26 Sep 2017
macOS High Sierra (10.13)
Apple released macOS High Sierra yesterday. You can read more about it here.
Mailplane 3 runs on macOS High Sierra. Just make sure you’re on the latest version (3.7.0 or later) by going to “Mailplane 3 > Check for Updates…” or downloading it before you upgrade to macOS High Sierra because older versions won’t start.