Hello JWHawkins,
Thanks for reaching out to Apple Support Communities. We see you have some questions about your mail server settings, and we'd like to help. The following link may be able to assist, as it walks through server settings, which may be the ones you're looking for: iCloud Mail server settings for other mail client apps
With these iCloud Mail server settings, you can set up your email client app to send and receive email with your iCloud Mail account. You need these server settings when you manually configure your email client app.
Let us know if this helps.
Regards.