We at Mutant Mail believe, every email has it's own identity. And as such, they should have their own display name, that you can set up.
It's one of the simplest process on Mutant Mail.
Go to your "Email IDs" tab on Mutant Mail dashboard.
Look for email id created on Mutant Mail. (If you can't find it, use the search function).
Click immediately below your email id (It says be default, "Add display name").
Type in the display name you want to show for that email id.
Click the Save button next to the text box.
Voila, your new display name is set for your email id.
Just a note, in case you don't have a display name set for your email id, we use your account name as display name by default.