You can change your Craft account email address from your account settings.
Change Your Email
Click or tap your profile picture
Click Change Email in the email field
Unable to Change Email
You can only change your account email to an email address that doesn’t currently have a Craft account.
If the Email Is Already in Use
If you need to use an email that’s associated with another Craft account:
Delete the account that uses the desired email address (go to Settings → My Account → Delete Account)
Once deleted, the email becomes available for use with your remaining account
Change the email in your active account (Settings → My Account → Change Email)
Deleting an account will permanently delete all documents in that account. Make sure to back up any important data before deletion.