Only a Newsgroup account If possible tell Thunderbird that you want to create a Newsgroup account. If you must tell it to be an client be careful to tell it to NOT download your mail to the local machine and that you do NOT want to delete mail from the server. I didn’t run into the issue with an account on the latest install but it was a problem for many students last year.
First Follow the set-up instructions for mail before the newsgroup setup. Follow the instructions but on the last step UNCHECK THE BOX. Otherwise it may move all your mail permanently off the server. UNCHECK THIS!
Be sure to check on the box for leaving mail on server.