How to access me.com email from iCloud web?

I have an older me.com email address, I'll call it abc.xyz@me.com. I set this up in my iPhone 4 some time ago to access email from that device, but not through iCloud; that is, I get that email just through Settings => Mail, Contacts, Calendars.

It works fine on the iPhone, but I want to access the email from a web browser. I sign in to icloud.com, click on the Mail icon, and a message says "iCloud Email Needed":

Ok, I go back to my iPhone => Settings => iCloud => Mail which is OFF (I've turned on only Bookmarks and Find My iPhone). I tap the OFF button for Mail, and it says:

Of course I don't want a NEW email address. I just want my old abc.xyz@me.com address in iCloud. So when I tap Create and enter the old address, I get:

Seems I'm in a Catch-22 situation.

How can I access my current me.com email on the iCloud.com website?