astravo

Mail, calendar, contacts and files for your organization

An alternative to Google Workspace and Microsoft 365. People sign in through your own identity provider, and Apple Mail, Thunderbird and Outlook work alongside the web app and the iOS app.

Sign in

What's in it

  • Mail

    Conversations, fast full-text search, snooze, scheduled send and undo send. Server-side filters you can import from a Sieve script, Gmail or Thunderbird. Aliases, groups, shared mailboxes with send-as, and out-of-office replies.

  • Calendar

    Day, week, month and agenda views. Recurring events, time zones, and invitations other calendar systems understand. Rooms and resources book themselves, and sharing works like Exchange: everyone in the organization sees your free/busy, and you choose who sees more.

  • Contacts

    Personal address books and a global address list with titles, departments, phones, managers and direct reports. It fills in addresses as you type and syncs to phones and desktop apps over CardDAV.

  • Files

    Folders, previews, version history and trash. Share with people in your organization, or send a public link with an optional password and expiry. A link can also ask for uploads.

Privacy

Remote images stay blocked until you ask, known trackers never load, and images are fetched through Astravo, not by your browser.

  • Personal aliases

    One click makes an address such as quiet.otter481@example.com to give out instead of your own. Replies go out from the alias, with nothing of yours. Pause it, block a sender on it, or delete it. Aliases never show up in the directory, autocomplete, free/busy or out-of-office replies.

  • Sender logos

    Logos come from senders' BIMI records and are looked up when mail arrives, so opening a message tells nobody anything. An uncertified logo only shows for senders people have had mail from for two weeks, so a new lookalike domain can't borrow a bank's logo.

  • Private events

    Private events stay private in the web app, over CalDAV and in published calendar feeds.

Delivery and spam

Everything Astravo sends is DKIM-signed, including bounces and forwards.

  • Signing

    RSA and Ed25519 keys. A new key only starts signing once its DNS record is visible. Existing keys can be imported, so a domain moving in keeps its DKIM record.

  • Spam filtering

    Incoming mail is checked with SPF, DKIM and DMARC and scored by Rspamd. Moving a message into or out of Junk trains the filter, in the web app, on the phone or in any IMAP app. Each organization teaches its own filter.

  • Transport

    MTA-STS, TLS-RPT, SRS for forwards, and a retrying outbound queue.

  • IPv6

    Every listener speaks IPv4 and IPv6. Outgoing mail tries IPv6 first and falls back to IPv4 when a receiver refuses the IPv6 connection.

For administrators

One Go server on Postgres. Many organizations on one install, each with its own domains, admins and identity provider.

  • Your sign-in

    People sign in with your OpenID Connect provider, so passwords never reach Astravo. Apps that can't do OAuth get app passwords, revoked one at a time.

  • Admin console

    People, shared mailboxes, rooms, groups and aliases. A DNS guide that checks every record, central email signatures filled in from the directory, the mail queue and an audit log. An organization's admins see only their own.

  • Moving in

    People import their old account themselves, or an admin does it for them: mail, calendars, contacts, filters and the out-of-office reply. New mail keeps copying every few minutes, so the MX switch can happen whenever it suits.

  • From mailcow

    A whole mailcow server moves at once: domains, DKIM keys, aliases and the spam filter's training, for every mailbox.

Apps

Astravo's own apps are where everything works. Other apps connect over IMAP, SMTP, CalDAV and CardDAV and get what those carry.

Web app
Everything. app.astravo.eu
iOS app
Everything, with push notifications. In progress.
Apple Mail, Calendar and Contacts
Set up in one tap with a configuration profile.
Thunderbird
Configures itself through autoconfig.
Outlook
Configures itself through autodiscover. Mail only: Outlook doesn't speak CalDAV or CardDAV, and Astravo doesn't implement Microsoft's Exchange protocols.
Android
Any IMAP mail app, with DAVx⁵ for calendars and contacts.

Not there yet

Astravo is new. These are missing for now:

  • An Android app, which comes next
  • Office document editing and video calls
  • S/MIME and PGP
  • JMAP
  • Imports from Microsoft 365, and of Google calendars and contacts