Cannot add my email account

I've had a Mac Pro for years running High Sierra. The Mac or the OS kept changing my outgoing email server which prevented me from sending emails. I finally gave up on both the Pro and the OS and bought a refurbished Mac Mini with Mojave as the OS and used migration assistant to move everything from the Pro to the Mini hoping that my email problem would not follow. Now I am unable to set up my email on the Mini. I fill out the info needed to add an account (name, email, password) and click 'sign in.' The little spoke wheel just spins; for hours, and if I let it, it would spin for days. Doesn't matter what I do or how I do it I am unable to set up or add my established email to this computer. I know all the info is correct because I can access my account on my provider's site and I receive and can send email on my iPad. High Sierra would change the outgoing server to smtpauth.wowway.com. Didn't matter that I edited it numerous times, it always reverted to the wrong server and the wrong port. How can I get my established email account loaded onto my Mini?