Private Page Email Subscription Rules

[Eric Trebilcock]

We have a private StatusPage and I'm noticing that when someone uses the subscribe to updates button, they are able to put in any email address.  Is there a way to lock this feature down to reject email self subscription requests if the email domain doesn't match with a pre-defined list?  There are only certain email domains that we want emails sent to for notifications but I am not seeing how to put that type of restriction in place.