I am still receiving emails on an old Apple ID address
On your Apple ID, there are three places where you can have an email set under Name, ID, and Email Addresses.

1.Apple ID and Primary Email Account - This is the email account that is associated with the user name of your AppleID. It is the email account that you enter when you log into your account or when you try to buy something on the iTunes store.

2.Alternative Email Addresses - These are addresses that you set up for your account that are also associated with your Apple ID. They are usually an @icloud.com or an @me.com. It is possible that the email is there, but you probably would have seen and removed it from there.

3.Notification Email Address - This one is towards the bottom of the page and may have been missed, especially if you updated on a MacBook or laptop screen. Your notification email address will be used in addition to your primary email address to notify you when changes are made to your account.

If it is not in any of these three places on your Apple Account, then you may need to get in touch with Apple Support.

You can also go to the mail settings and click off the notifications emails from Apple, that way they don't come to you.

One other possibility is that if you at some point in time had two Apple IDs or that someone else had your email on their account (family member, etc.), it could be possible that that one is still active and has the email you are receiving emails from on. So if you had a personal Apple ID and one for work or one for a sibling, maybe the email you do not want to receive emails form anymore is set there. 

Best of Luck.