Turn off Hide My Email Permanently

Greetings imavinashkanaujiya, 

It doesn’t appear that you can disable this feature, as it is a part of an iCloud+ subscription. However, you can opt not to use it. 

For example, to use it when sending an email in the Mail app it has to be purposefully enabled - Use Hide My Email in Mail on iPhone

Send an email with Hide My Email

1. Tap the compose option.

2. Add a recipient and subject for your email.

Note: You can only send a message using Hide My Email to one recipient at a time.

3. Tap the From field, tap it again, then tap Hide My Email. A new, unique email address appears in the From field.

Tip: When the recipient replies to an email you sent with Hide My Email, their reply forwards to your real email address. To set a Forward To address, see Create and manage Hide My Email addresses in Settings.

You can manage any addresses created with the feature though, such as removing them - Create and manage Hide My Email addresses in Settings on iPhone

You can create and manage Hide My Email addresses in Settings. Go to Settings > [your name] > iCloud > Hide My Email,

Thanks.