There are two ways to use Hide My Email: With Sign in with Apple, which lets you create an account using a randomly-generated email address directly within a supported third-party app or website. Or with iCloud+, which lets you generate as many random email addresses as you need on your device, in Safari, or on iCloud.com, which you can use for whatever site or purpose you choose.
Hide My Email generates unique, random email addresses that automatically forward to your personal inbox. Each address is unique to you. You can read and respond directly to emails sent to these addresses and your personal email address is kept private.
If you create an account with an app or visit a website that supports Sign in with Apple, you can choose to share your email address, if you're familiar with the app or website, or hide your email address, if you'd prefer more privacy. If you choose the Hide my Email option, only the app or website you created the account with can use this random email address to communicate with you.
With an iCloud+ subscription, you can generate unique, random addresses from your iPhone, iPad, or iPod touch with iOS 15 or iPadOS 15 or later in any email field in Safari. You can also generate email addresses on-demand in the Settings app or on iCloud.com.
Apple doesn't read or process any of the content in the email messages that pass through Hide My Email, except to perform standard spam filtering that's required to maintain our status as a trusted email provider. All email messages are deleted from our relay servers after they're delivered to you, usually within seconds.
With Hide My Email active whenever you are asked by a website to register, it will give you the option of using a unique eMail address that is forwarded to you.
At any time, you can change the email address that receives forwarded messages. Or you can choose to turn off email forwarding to stop receiving messages. You can manage your addresses created with Hide My Email in Settings on your iPhone, iPad, or iPod touch, or on iCloud.com.
Unless I really want a website to know my real email address I am usually using Hide My Email and if I notice an increase in unwanted emails coming to that address I simply deactivate the address.