How can I add an Apple email address to an email client such as Evolution? I somehow ended up with an Apple email address.

How can I use my '@me.com' email in my email client (Evolution in Debian)?
You can find the IMAP settings to use for your mail client at this support article.

Incoming mail server

Server name: imap.mail.me.com
SSL Required: Yes
Port: 993
Username: example@me.com (use your @me.com address from your iCloud account)
Password: Your iCloud password


Outgoing mail server

Server name: smtp.mail.me.com
SSL Required: Yes
Port: 587
SMTP Authentication Required: Yes
Username: example@me.com (use your @me.com address from your iCloud account)
Password: Your iCloud password