Would like a refund

Thank you for your donation. You are never required to make one to download, install, or use Thunderbird. It is a totally free, open source program. Here is Thunderbird's refund policy. https://give.thunderbird.net/hc/en-us/articles/49703731547667-Cancellations-and-Refunds When setting up a new email account Thunderbird's setup wizard makes a best-guess at the server settings, but it's not always right, especially with lesser-known providers. In that case, it's best to come armed with the proper settings, usually found at the provider's help web pages. I found these, which may be helpful. https://www.dynadot.com/help/question/POP3-SMTP-settings https://www.dynadot.com/help/question/basic-email-thunderbird What you show in your screen shot looks wrong to me. I doubt that the IMAP server is simply "dynadot.net". Usually there is more to the host name than that. Also, I notice that dynadot only offers IMAP connection for their paid "Pro" plan, which you may or may not have.