What do you mean by “signed with” - I think of emails signed with a signature file. Could you take a screen clip of exactly what it is that is bothering you so we can see what it looks like?
The sending name (apart from any separate optional alias) is usually the name that appears setup in your Account.
Go to “Menu / Accounts” and click on your account. In the “General” Tab you will see the “Name” which is the sending name when you compose email. So could be that you that email address [email protected] you mentioned is in the Accounts Name field instead of your actual name.