I use the GPG Suite often, and it's always great, incl. Apple Mail integration. However, the current developments are downright harrowing. The final update to macOS Sierra has already been released, with High Sierra on the horizon, and GPG Suite is still in public beta, so I'm still twiddling my thumbs on El Capitan. (GnuPG v2.1 integration is also taking forever.) And I don't accept excuses. Other Apple Mail plugin developers have been fast in upgrading their software for Sierra compatibility, again and again, and if the GPG Suite developers can't keep up, they need to think about going for a paid product, not just donations. Don't get me wrong, it's a great software, but the last year—THE LAST YEAR!!!— has been frustrating, to put it mildly. I don't believe the developers realize the negative emotions they're spawning. This needs to stop. This needs to come around fast, super fast, like yesterday.