New accounts are set to the One-password mode by default. This password is used for login (to verify the identity of the user) and for mailbox (to decrypt data). For most users, a single password provides security and convenience.
However, it is still possible to switch to Two-password mode following these steps:
1. Go to Settings at the top right and click on Go to settings.
2. Select Password & recovery in the sidebar and activate Two-password mode.
3. You will be asked to enter your old password and a new password. Click Save once you have entered both passwords.