imessage on MACbook pop up

Thanks a million for the heads up. Let me correct my stupid self. First, any devices that have any services signed into with your Apple ID will appear under your Apple ID marquee in settings on your iOS devices (scroll down to the bottom.) In macOS, you have to go into iCloud preferences, click on Account Details and then the Devices tab. Either way, if you don’t see any unknown devices then you should be OK on that front. Second, if FaceTime is disabled on a device, it doesn’t necessarily mean you’re not signed into FaceTime on that device! On the Mac, in FaceTime preferences, regardless of whether it’s enabled, if the Sign Out button is actively black and white, you’re signed in and you just click the button to sign out. On the iOS device, in FaceTime settings, if it’s disabled, toggle it on and then, if it’s signed in, it will enable without prompting you to sign in at which point you click on your Apple ID and sign out. Otherwise, if you’re not already signed in, it’ll prompt you to sign in at which point you just cancel. Anyway, if you got the email and no unknown devices are signed into, I’m confident you’re inadvertently signed into it on one of your devices but, as you have by now surmised, I could easily be wrong.

It'll do that each and every time you sign in or even re-sign in to FaceTime, Messages et c. even if it's not actually a new device and even if it's not the first time it was signed into on that device.

Fear not, though. Any and all devices that are signed into any or all of iCloud, FaceTime, Messages, iTunes & App Store et c. with your Apple ID will appear in your iCloud devices list which you can access via iCloud settings on your iOS devices as well as iCloud preferences on your Macs.

This used to happen to me. Many times. Always right after I updated macOS or iOS and sure enough would find FaceTime had inadvertently been enabled on one or another of the devices. I think the Setup Assistant would enable it by default albeit with confirmation dialog in which I guess I would inadvertently touch "next" without toggling it back off. A couple of years ago, I once had reason to use FaceTime and thought it was cool so I enabled it across the board and have kept that way and the subject effect hasn't happened since. Anyway, I believe that once you're signed into iCloud it only takes a simple toggle to enable FaceTime.

Are you sure the message is legitimate? Does it contain a link for you to sign in somewhere? It may be a scam.

Apple will always address you by your name or the name they have on file for you, not Dear Customer, Dear Client or by using your e-mail address. The e-mail will be from @apple.com or @iTunes.com. E-mail addresses can be spoofed. You can go to Mail/View/Message/Show all Headers to see more. Apple e-mails will never contain an attachment. Apple will never request personal information such as Social Security numbers.

The only exception to the above I have noticed is if you order something from the Apple Store (apple.com), your receipt will be addressed to Dear Apple Customer. That is a receipt for a purchase you initiated.

Avoid phishing emails, fake ‘virus‘ alerts, phony support calls, and other scams

Identifying legitimate emails from the iTunes Store

Send the e-mail to Apple as an attachment to a new e-mail before deleting it. You can forward as an attachment by going to Mail/Message/Forward as attachment.

reportphishing@apple.com

• An Apple ID is being used message
• An Apple ID is being used message