Email to let you know you can work again

In Settings > App, there is an option for this as the last option. You can opt in daily, twice weekly, or once weekly. If you have an iOS device, you could use Tsurukame, which can give you notifications (not by email) whenever your reviews and/or lessons are ready in real time. (I don’t know what’s available for Android, unfortunately. Someone else most definitely does, though, so here’s to hoping someone who knows about it will come help if need be!)