You need to speak to your email provider help desk to do that. Thunderbird does not have that ability.

Okay so I can't connect this email provider to my domain. Can you suggest some e mail providers that would work with squarespace.

Maybe if you provide some explicit details, someone here may be able to help you. My inference is that your domain is with squarespace? I did see this URL that indicates they support what you are desiring. https://www.squarespace.com/blog/how-to-set-up-an-email-for-your-business