Hide My Email is an Apple feature which is defaulted to "enabled" at the point of creating a Broadband Go account. As the name suggests it will hide the email address associated with your Apple ID and often appears in the following format firstname.lastname@example.org
If you do decide to leave the function enabled, don't worry it will not affect the delivery of any email correspondence between Broadband Go and yourself.
Alternatively, if you would prefer to disable "Hide My Email" then simply untick the box before moving on to the next step of account creation.
More detailed Apple article is below:
Hide My Email lets you create unique, random email addresses to use with apps, websites and more so your personal email can stay private. It's built-in to Sign in with Apple and iCloud+.
Hide My Email is a service that lets you keep your personal email address private, whether you're creating a new account with an app, signing up for a newsletter online or sending an email to someone you don't know very well.
There are two key 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.
How Hide My Email works
Hide My Email generates unique, random email addresses that are forwarded automatically 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. Find out more about Signing in with Apple.
- 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. Find out more about iCloud+.
Apple doesn't read or process any of the content in the email messages that pass through hiding 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.
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.