Connect Spacemail to Sickle

Spacemail, the email service from Spaceship, lets mail apps sign in with your normal mailbox password — there is no app password to create, and IMAP is switched on for new mailboxes. Sickle needs Spacemail's server name once; it is the same for reading and sending.

Add the mailbox once, on the web or in the Mac app, and it shows up in both — and in every agent you have connected to Sickle.

Before you start

• A Sickle account. If you do not have one yet, start a free trial.
• Your full Spacemail address and its mailbox password — the one you use in Spacemail webmail, not your Spaceship account login.

Check IMAP is on

Spacemail turns on access for mail apps by default. If you or an admin may have turned it off, check first:

1. In Spacemail webmail, click Settings in the top-right corner.
2. Find the IMAP/SMTP/POP3 card and click See configuration. Make sure access is on.
3. You can do the same in Spacemail Manager: click the three dots next to the mailbox's Spacemail subscription and choose IMAP/POP3/SMTP.

Spaceship's own instructions are in Connect Spacemail to an email client.

Spacemail's server settings

• IMAP server — mail.spacemail.com, port 993, SSL.
• SMTP server — mail.spacemail.com, port 465, SSL. The Mac app sends the mail you write through it, and so does your agent when you approve a send.

Connect on the web

1. Sign in at sickle.app and open Mailboxes.
2. Click Connect mailbox and choose Other.
3. Enter your Spacemail address and mailbox password. For IMAP server enter mail.spacemail.com and port 993; for SMTP server, mail.spacemail.com and port 465.
4. Click Connect. Sickle signs in to Spacemail to check everything before it saves; you see Checking… while it does.

Connect in the Mac app

1. Click + at the bottom of the sidebar (Add mailbox). On first launch, the onboarding screen shows the same choices.
2. Choose Manual authorisation (⌘7).
3. Enter your Spacemail address. Under Inbox settings (IMAP), enter the mailbox password, mail.spacemail.com and port 993; under Outbox settings (SMTP), the same password with mail.spacemail.com and port 465.
4. Click Sign in.

Check it worked

The mailbox appears in the list on the Mailboxes page. If you have an agent connected, ask it "Which mailboxes can you see?" — the new one is there, with nothing to reconnect.

Troubleshooting

• "Authentication failed" or "The mail server rejected these credentials". Check you entered the full address and the mailbox password, not your Spaceship account password. If the mailbox password was reset in Spacemail Manager, use the new one.
• "Could not reach the mail server". Both servers are mail.spacemail.com. Check the ports: 993 for IMAP, 465 for SMTP.
• It worked, then stopped. The mailbox password changed, or IMAP access was turned off. Turn access back on, or enter the new password in the Can't sign in notice in the Mac app.

Disconnect

On the Mailboxes page, click Disconnect next to the mailbox. Spacemail has no app passwords to revoke; to cut off every mail app at once, change the mailbox password in Spacemail Manager.

Next: connect your agent

Your Spacemail is ready for any agent you connect to Sickle. Pick yours: Claude, Claude Code, Codex, Cursor or OpenClaw.