In order to complete this process, you will need to know the current password for your 1&1 Mail Business e-mail so that you are able to log into the webmail interface and set a new password.
Login to your email by visiting webmail.1and1.com
Click the gear icon and then select Settings.
Select Change Password from the Settings menu.
Enter your current password in the text field and then enter your new password twice. When you are finished, click the Change Password button.