@Override
    public void setEmail(String username, String email) throws UserNotFoundException
    {
        getUserProvider(username).setEmail(username, email);
    }
Changes the email address of a user in the first provider that contains the user.

@param username the identifier of the user.
@param email the new email address of a user.
@throws UserNotFoundException when the user was not found in any provider.
@throws UnsupportedOperationException when the provider is read-only.
xmppserver/src/main/java/org/jivesoftware/openfire/user/UserMultiProvider.java