Thank you, EarthKid. Apple can be infuriating. You found a "loophole" to get around their seemingly-purposeful ways of making things difficult. In case you are a new reader of this thread, let me lay out EarthKid's solution.
The Problem:
If your AppleID is something like XXX@mac.com, then you can't change it to anything else. Why not? Who knows? That's just apple
But worse, if you somehow set your "primary email" address for for your AppleID to match your AppleID name (as they suggest), then now your emails are going to XXX@mac.com. And unless you've been paying some subscription fee, those emails are completely inaccessible!
It gets worse. Because now you can't change your primary email back to something useful again, at the AppleID site! So, verifications, receipts, whatever, go into the great beyond. The stuff up above is simply annoying. *This* is the problem.
The Solution, thanks to EarthKid:
You can't fix it through the AppleID site (why? who knows.), but you CAN fix it through the apple online store. Go to the online store (apple.com -> store) and sign into your account. There, under "edit payment information" (why there? who knows...) you can change the address from the stupid XXX@mac.com to something else.
And if you go back to the AppleID site, you will see that, indeed, while your AppleID will never change, at least your "primary email address" has been changed!
Oh, and you'll see a message with a "helpful suggestion" to make your primary email address the same as your (mac.com) AppleID. Don't.
