ihasmail

ihasmail is a webmail client for Stalwart Mail Server. It handles mail, calendars, contacts, file storage and Sieve filters in a single responsive interface that works on a phone as well as a desktop monitor.

It speaks JMAP and nothing else — no IMAP and no SMTP — which is what lets it stay this thin. The browser never talks to the mail server directly; the ihasmail server makes every upstream call itself.

The distinguishing property is that it can run with a read-only filesystem and no volume at all. There is no database and no mail store, because everything durable already lives on Stalwart, including each user's own settings. An instance is its container image plus an environment file, so upgrading is a replacement rather than a migration and there is nothing to back up.

Requires Stalwart 0.16 or newer.