macOS 11 through 11.5 Catalina, instructions based on macOS X 11.4 (Big Sur)
1. Open Apple Contacts
2. Select menu "Contacts" -> "Add Account..." or menu "Contacts" -> "Preferences..." and then click the Accounts icon, and then click "+" at the lower left to add an account
3. Select "Add Other Account..." -> "CardDAV account" or "Other CardDAV Account..." and click Continue
4. Enter:
- Account Type: [Manual]
- User Name: (your full email address)
- Password: (your email password)
- Server Address: secure.prxy.com
5. Click "Sign In"
6. Select the apps to use with this account:
- check Mail
- check Notes (if you wish to use Apple's Notes app, this will store your notes on the mail server)
7. Click "Sign In"
8. Select the account from the list on the left
9. Update Description as desired
10. Close Preferences window
