I don’t have it on the promotional site right now, but here’s the breakdown:
Receive unlimited mail, 500MB storage: Free
Send unlimited mail*: $1/month
2GB extra: $2/month
10GB extra: $6/month
20GB extra: $10/month
100GB extra: $20/month
1TB extra: $40/month
There are upcoming features that I haven’t done the market research and cost analysis for yet to determine pricing, but these are the features that are still in development:
Native mobile app (right now it’s a PWA): Free
IMAP/SMTP/CardDAV for third party clients and to import/export/sync: Undetermined price
Custom domain with unlimited addresses: Undetermined price
Additional users for you custom domain: Undetermined price
The reason for charging $1/month to send email is so that spammers won’t use my service to send spam. A spammer is very unlikely to divulge their real payment information.