Introducing TACENZA Mail

We’re building TACENZA Mail: business email for your own domain, from CARTIQO. It’s built the same way as TACENZA Chat. It knows as little about you as it can, it doesn’t track what you read, and it says plainly what it can’t do. The goal is privacy like Proton Mail, with what businesses need on top, starting with shared addresses for teams. It’s private for now, and sign-up isn’t open yet.

What it is

You get addresses like [email protected], a web app to read and write mail in, and a mail server that also works with Outlook, Thunderbird and the mail app on your phone.

The mail server is Stalwart, an open-source server for sending and receiving mail, spam filtering and signing. The web app and the small backend that signs you in are ours.

What’s built

• Your own domain, with DKIM signing, SPF and DMARC set up per domain. The mail server shows exactly which DNS records to add.
• Reading. Folders with unread counts, a message list and a reading pane. HTML mail is shown as the sender designed it, cleaned and locked in a sandbox where nothing in it can run.
• No tracking pixels. Images from the internet stay hidden until you click Show images, because loading them tells the sender that you opened the mail, and roughly where you are. Images sent inside the mail show right away.
• Shared addresses. A company can have addresses like support@ and billing@, and its admin decides who has each one. Everyone on an address sees its inbox and replies as it.
• Assigning mail. In a shared inbox, assign a message to someone, take it yourself, and mark it done.
• Conversations and search. Replies are grouped with the message they answer. Search finds mail by words, “exact phrases”, from:, to:, subject:, has:attachment and is:unread. The text of encrypted mail can’t be searched, because the server can’t read it.
• Team settings. The company’s admin adds and removes people, resets forgotten passwords and decides who has which shared address.
• Signing in. Two-factor sign-in with any authenticator app, and a separate app password for each mail app, which you can remove on its own.
• Zero-access encryption, which you can turn on. More on that below.

The web app makes no requests to anyone else: no analytics, fonts or scripts from third parties.

Encryption, and why it isn’t end-to-end

Turn on zero-access encryption and new mail is stored encrypted with a key only you have: the text and attachments of mail you get, and your copies of mail you send. Your password unlocks it. A recovery key, shown once, gets you back in after a password reset.

That still isn’t end-to-end, and we don’t want anyone to think it is.

• Mail from other providers arrives unencrypted, because that’s how email works. We encrypt it with your key the moment it’s stored.
• The provider on the other side can read what you send them.
• Who a message is from and to, its subject and its date stay readable to us.
• Your password passes our server when you sign in. We don’t keep it, but for now that’s a promise, not something you can check. Signing in without the server ever seeing your password is on the roadmap.
• Shared addresses are encrypted a few seconds after mail arrives, not before it’s stored.

If a conversation must stay between two people, use TACENZA Chat.

Other honest limits

• A company admin can reset your password. Without encryption, that lets your admin into your mailbox. With encryption on, a reset doesn’t open your encrypted mail.
• Signing out can’t yet cancel your session on the server. A copied session keeps working until it runs out.
• Too many wrong passwords lock the web app for 15 minutes. Someone who knows your address could use that to lock you out of the web app for a while. Mail apps aren’t affected.

Keeping spam out

Spam from one account hurts delivery for everyone, so Mail has limits built in. New accounts can only send to a few people at first, and the limit grows with the account’s age. Nobody can send mail with someone else’s From address. Every message has a Report button, and accounts that send abuse can be suspended. The Acceptable Use Policy has the details.

What isn’t built yet

• Sign-up is built, but not open. Before we open it, it needs real use by a few people, and there’s no billing and no support desk yet.
• Encryption for drafts, and for mail you move in from other providers, isn’t there yet.
• Drafts that save as you type, and searching inside encrypted mail, aren’t there yet.
• Calendar and contacts, and a guided setup for your own domain, are still to come.
• Moving mail in from Gmail and Outlook is planned for the invite-only beta.

What’s next

First, we run our own domains on it, on a server in the EU, for at least three months. Then friends and family, then an invite-only beta with plans and billing, and only then open sign-up. We’ll open it to others once it’s boring and reliable.

Until then, TACENZA Chat is where to start.