# Connect mailbox.org

<PlanNote plan="basic" />

You connect mailbox.org over **CalDAV** with your mailbox.org address and an **application password**. You create it in two minutes right in your mailbox.org settings — after that everything runs automatically, and sync picks up changes **every 5 minutes**.

:::caution[The most common pitfall]
For external programs like Kalender Sync, you create a dedicated **application password** at mailbox.org. If you have **two-factor authentication** enabled it's mandatory — your regular password no longer works here. Without 2FA the application password is optional, but recommended.
:::

## 1. Create an application password

1. Sign in to mailbox.org and open **"Settings"** → **"Security"** → **"Application Passwords"**.
2. Choose the application **"Calendar and address book client (CalDAV/CardDAV)"** and give it a label (e.g. "Kalender Sync").
3. Click **"Add new password"**.
4. **Copy the password shown** — for security reasons it's only displayed once.

## 2. Connect in Kalender Sync

1. In the dashboard: **"Connect calendar"** → **"mailbox.org"** → **"Continue"** to the form.
2. Enter your **mailbox.org email address** (e.g. `name@mailbox.org`).
3. Paste the **application password** and click **"Test & Connect"** — Kalender Sync verifies the connection immediately.

You don't need to enter the server address — Kalender Sync knows it and finds your calendars automatically.

## If "sign-in failed" appears

- Did you really use the **application password**, not your regular mailbox.org password?
- Best to paste the password fresh instead of typing it.
- Password deleted in your mailbox.org settings in the meantime? Simply create a new one (step 1).

:::note[Birthday calendar]
mailbox.org automatically creates a **"Birthdays"** calendar. At mailbox.org it is read-only — use it at most as a **source** for a one-way sharing, not as the target of a two-way sync.
:::

## Ending access

In Kalender Sync: [remove the calendars](https://docs.kalender-sync.de/en/connect-calendar/disconnect/). You can also delete the application password any time in your mailbox.org settings under **"Security"** → **"Application Passwords"** — access ends immediately.