Thanks for the informative answer.

The business model seems to be subscription based which i like(decently priced imo).

i suggest you looking into supporting external mail clients like k9/fairemail. Emails being encrypted at rest would be big.(People like to keep their stuff private even from the provider). Having a web app is nice tho.

i hope your ventures into this become succesful.

what is the business model for this service?

i couldnt find a privacy policy.

Sorting emails like this is really useful.

host your own instance and use that for your account.

if you can’t host, you’ll have to trust somebodies instance like you do with reddit etc