why is my email not coming in

My first suggestion is to access your account via your email provider's website. That will get you the important messages. Fixing settings in thunderbird is a lower priority. To get assistance for that, I suggest you post screenshots of error messages, plus screenshots of the server settings pane and the SMTP server settings pane. I included a snapshot of where to locate those panes. A brief statement on what is wrong will also help. thank you