You get 500MB free storage, and you can receive unlimited email. Here’s the breakdown of subscriptions:
$0.99/month to send unlimited messages.
$1.99/month for 2GB
$5.99/month for 10GB
$9.99/month for 20GB
$19.99/month for 100GB
$39.99/month for 1TB
I’m working on a mobile app that will be free. For now, the web app is a progressive web app, so you can install that to your home screen and it works like a mobile app.
I’m also working on other features that aren’t ready yet, but they’ll be premium features:
IMAP, SMTP, and CardDAV support.
Custom domain support.
Additional users for your custom domain.
So basically the business model is pretty similar to other email services. One difference is that I charge for sending mail, and basically that’s to prevent spam. Spammers are unlikely to use a real payment account, because it will get shut down when they’re caught spamming.