When you try to set up a new account in Thunderbird, the 'automatic set up' wizard tries to look up the settings for your email provider in a database. The settings for many providers are listed there, but by no means all of them. The message is simply telling you that Thunderbird couldn't find your provider listed in the source it is using. Under those circumstances you have to set up the account yourself. Your email provider should provide those settings for you, most likely on their website. Once you have them enter them in Thunderbird like this: https://support.mozilla.org/en-US/kb/manual-account-configuration