I have a list of several email accounts within thunderbird but realized that one of them recently disappeared. When trying to re-add it under File-New-Existing Mail Account, I enter the email address and password. I click continue, and the configuration is found. It is an IMAP account, so I click done. The screen says "checking password," then the message states "configuration could not be found - Is the username or password wrong?" I am able to log into my email account at Cox.net without a problem, and I do not have 2-factor authentication turned on anywhere. How do I re-enroll my email account that disappeared? Also, any ideas as to why it disappeared from the list of email accounts in Thunderbird? Thank you.