when I first signed up to ntlworld many years ago they game me a default email address, which has become my default username. firstname.lastname@example.org and ive been stuck with it.
but a while ago I seen you could change the contact email address, thinking I could at last delete that old email address which the scammers love, losts seam to have that email address.
1, If i login with my account email (now changed) email@example.com I can edit add and change upto 10 email addresses, but the account email address firstname.lastname@example.org is not listed anywhere, but anyone sending email to it, gets forwarded to my contact email address.
Do you know if email@example.com is your primary email address, if this is your primary email address, we cannot delete it but you should be able to change your username to a different username.
I can take a further look into this for you by a private message, so that I can check the status of your account and email address. Would you like me to do this?