I have three email accounts on T-Bird 45.4.0. I want to add an email account that already exists on another computer, not create a whole new account. I want to put it on my computer too. When I try to add another account I get a box that says "Would you like a new email address" and at the bottom has two boxes. One says "skip this and use my existing email," The other says "I think I'll configure my account later" When I click on either, nothing happens.

Thanks for any advice