This article will explain how to change your display name in 123-mail webmail.
Login to the 123-mail webmail.
Click on the Configuration icon in the main toolbar.
Click on the User folder in the left hand pane, and then click on the subfolder Personal Data
Click on the Display name text box and edit your display name.
Click the Save icon to store the changes made.
Please Note: You must log out and log back in to 123-reg webmail for the changes to take full effect.