Start a new email

Click Compose (top left, blue button) to start a new email.

The compose window

The compose window opens as a tab. Fill in the recipient (To) and Subject, then write your message.

You can paste images directly into the message body and attach files using the paperclip icon. Hover over any toolbar icon to see what it does.

When you’re done, click the green Send button (top left).

Tabs

Compose opens in its own tab. The first tab (Mail) always stays open — it shows your inbox and folders. Other tabs (Compose, Settings, opened emails) can be closed with their ×.

Note: clicking the × on the first (Mail) tab closes all other tabs, but the main tab stays open.

Open email in a separate window

Prefer separate windows over tabs? Click the arrow icon (top right of the compose or email view) to pop it out into its own window. About half of users prefer this.

Once you choose a separate window, subsequent emails open the same way. Click the same icon inside the window to bring it back into a tab.

Can’t find your compose tab?

Don’t panic. If your draft had a subject or any text, Arca saved it automatically to the Drafts folder. Find it there with its date and time, and pick up where you left off.

Attaching files

Click the paperclip icon to attach a file. The attachment appears at the bottom of the compose window. You can also paste images directly into the message body.

Hover over any icon in the toolbar for a tooltip explaining what it does.

The unencrypted warning

If encryption is possible (Arca knows your recipient’s lock/public key), it warns you before sending unencrypted. Choose:

• Encrypt — send as an encrypted message
• Send unencrypted — send as regular email
• Cancel — go back and edit

You can turn off this warning per contact, or adjust it in Settings → Email.

The pre-send preview

Before sending, Arca shows you a final preview with a 10-second countdown — a last chance to catch a mistake. You don’t have to wait: click Send now to send immediately, or Cancel to go back.

Adjust the countdown timing (or turn it off) in Settings → Email → Preview. Follow the arrows in the screenshot to find it: ☰ menu → Settings → Email tab.

Sending encrypted email

To send an encrypted message, flip the Encrypted / Not Encrypted toggle at the top of the compose window. If your contact uses Arca, their lock is likely already on the server.

Click Send and you’ll see a preview of the encrypted message before it goes out — confirming you’re sending the right thing to the right person.

If the lock is missing

If the recipient’s lock isn’t on the server or in your local lockbox, Arca shows “Encryption lock required.” You have three options:

• Request the lock from the recipient — they get free instructions to set up Arca
• Search public key servers — in case they use another encryption app
• Select a lock from your lockbox — if you already have their lock saved locally

Without a lock you can’t encrypt. If you send as regular email instead, make sure to remove any sensitive content first.