In our Mozilla email application, Thunderbird email v31.4, we created another account for the same email (one email is imap, the other is pop). All was well these days until now. When needing to change setting we get message "an account with this name already exists". After googling we found that the problem was that we created another account with the same email address.
The strange thing was when creating the email Thunderbird never alerted us we were duplicating data.
How can we enter the settings of the account? Or delete one of the account?