iCloud email

Hello CherylW1985,

The steps in the previous reply are correct for protecting your Apple ID if you have concerns about its security. If you'd rather, you can change your Apple ID email address by following the steps here: Change your Apple ID - Apple Support

"How to change your Apple ID to a different email address

1. Go to appleid.apple.com and sign in.
2. In the Sign-In and Security section, choose Apple ID.
3. 
4. 
   
5. Enter the email address that you want to use as your Apple ID.
6. 
7. Choose Change Apple ID.
8. If you changed your Apple ID to a third-party email address, check your email for a verification code, then enter the code. Learn what to do if you didn't get the email.
9. If you use services like iCloud or Messages to share with friends and colleagues, sign in to those services with your updated Apple ID.

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.

If you see a message that the email address you want to use isn't available or is already in use, check that you or a family member aren't already using that email address with a different Apple ID. If a family member is using that email address, remove it from their account then try to use it. 

In some countries or regions, you can use your phone number as your Apple ID. But if your Apple ID is an email address, you can't change it to a phone number.

If your Apple ID is a phone number

You can change your Apple ID to a different mobile phone number.

Learn more

• To switch to a different Apple ID account—not change the email address that you use as your Apple ID—you can sign out, then sign in with a different Apple ID."

We hope this helps.

Cheers!

Hello CherylW1985,

Thank you for using Apple Support Communities.

What makes you think someone has been using your iCloud email address? Only one person at a time can sign into an Apple ID and use the associated iCloud account and email address. If you think your Apple ID has been compromised, you will want to take a look at this article for the necessary steps to take: If you think your Apple ID has been compromised

Best regards.

The same mail address can never exist on iCloud server , in which accounts credentials are totally different in different devices , in case if you revealed all account credentials to that person , still same credentials are used to sign in with the account , then change your Apple ID account credentials , its better to convert account into 2FA , when you contact apple support its wiser to deactivate account from server permanently How to delete your Apple ID account - Apple Support

Changing Apple ID address will only help not to view mails that are received in the iPhone ( the mails from their recipients ) .