Set up CardDAV Connection in iPhone/iPad Contacts

To configure a CardDAV connection between your iPhone and the mail.de address book, please follow these steps:

1. On your iPhone, tap "Settings", then select "Contacts", and then "Accounts".
2. Tap "Add Account ...".
3. Select "Other".
4. Select "Add CardDAV Account".
5. Enter the following details:
   Server: https://adressbuch.mail.de/
   Username: your mail.de email address or login
   Password: your mail.de password
   Description: a short description, e.g., "mail.de Address Book"
6. Tap "Next". Your information will be verified.
7. Once the connection is successful, the CardDAV account will appear in the list of accounts.
8. Your mail.de contacts will now appear in the iPhone contacts app.
   Under "Groups", you will find the mail.de address book.

Important note:

If you want all newly created contacts, which are not explicitly assigned to a specific account/address book, to be added to your mail.de address book by default, do the following on your iPhone/iPad:

1. Tap "Settings" and select "Contacts".
2. Under "Contacts", tap "Default Account" and select your mail.de address book.
3. Now select your mail.de address book.
4. From now on, every contact you create under "All Contacts" will be synchronized with your mail.de address book.