I Can’t Set My iCloud Mail As My Apple ID

Based on what I have read, I suggest you leave your Apple ID email address as a 3rd party email address because you have more flexibility if you need to change the email address. For example, if the Apple ID got compromised, you can change it to another address. I also have read of many people who were locked out of their accounts when they forgot their password. Since the recovery email address is the @iCloud email address, if you forget your password, you also can't access your email to get emails from Apple to recover your account. You can set a rescue email address, but for some people, this hasn't worked.

Yes, you’ll need to wait a month and then try again.

See -> Change your Apple ID - Apple Support

”If you can't change your Apple ID

If you try to change your Apple ID to an @icloud.com email address that was created within the last 30 days, you will be asked to try again later.”

I should have mentioned that you can already use that @icloud.com address as a login for your AppleID, without changing the primary email address of your AppleID.

My AppleID primary email address is a personal address using one of my own internet domains. And it is my iCloud AppleID and my iCloud has my @me.com address as an alias. So I can sign in using my one & only AppleID password, but with any of those three email addresses. Those addresses (my own domain email, my iCloud and my @me.com alias) are all synonymous login IDs for my one AppleID.

So your new @icloud.com address should work just fine as your AppleID login address now, regardless of what your AppleID listed primary email address is.

You are welcome. There may be other reasons you need to receive email from Apple, but for the most part, you should be okay.

Enjoy the iCloud ID.

You are welcome.