Hide My Email
Itâ€™s not really an iOS 15 feature by itself, but it does seem that the new iCloud+ Hide My Email service is also â€œcoming in a software update later this year.â€
This will allow iCloud Mail users to generate unique, random email addresses that forward into their personal inbox to protect their privacy and anonymity.
While there will undoubtedly be an iOS 15 component to this, since itâ€™s not very useful unless you can easily generate these email addresses on-the-fly, this update probably requires upgrades to be made on the iCloud backend as well.
Itâ€™s interesting, however, that the new iCloud+ custom domains donâ€™t have a similar footnote beside them, so this may involve more work on the iCloud side, or perhaps it is just a matter of waiting to release it until the user-facing parts of it are ready to go in iOS 15.