In group chat notify inviter about packet rejection

I have developed a openfire plugin to monitor flow of packets among users, which can restrict 2 users from chat if Admin has done so, it is working fine in peer chat in case like if there are 2 users user1 & user2, admin wants user1 should not do peer chat with user2 in this case it works fine and user1 get a message “not allowed” (customized message) if he tries to chat with user2 (I throw packet rejection exception in code to notify sender).

Now admin wants that user1 should not start group chat with user2 also works (user2 do not get chatroom invitation) but inviter do not get any response saying “not allowed” (like case in peer chat), so can anyone suggest me how can I notify the inviter by sending him message.

 I have checked Admin usecases for Group chat in RFC 0045 ([http://xmpp.org/extensions/xep-0045.html#ban](http://xmpp.org/extensions/xep-0045.html#ban)) which has Admin usecase to ban a user from group chat, can anyone suggest how can I use this RFC packet to notfy inviter.