Um, it doesn’t forward to their iCloud email address, it forwards to the email they use for their iCloud login - eg the primary gmail or whatever address. User

Um, it doesn’t forward to their iCloud email address, it forwards to the email they use for their iCloud login - eg the primary gmail or whatever address. Users have the option to provide their personal email address, but given the track record of these being sold it’s reasonable to expect users to not trust you. You can email them correspondence because as above that goes to their primary email. What you lose is the value of the email address as an asset.