User Messaging Restrictions?

Is it possible to restrict the ability to send messages to a certain group? I’m looking to use this in a school environment for the staff, and I would like to set it up so that the teachers group can send messages to the office, but not to each other, and so that the office can send messages to everyone.

Is this possible?

http://www.igniterealtime.org/community/docs/DOC-1370

This is also discussed here: http://www.igniterealtime.org/community/thread/31655. In this case the Packet Filter may be best due to the way you wish to restrict communication. Shared groups would probably not be a good idea unless you want to create frustration amongst your faculty. When you share a group to auto-populate to a roster, all members of the group get the shared group in their rosteer. This means when you share the faculty groups for the admin staff the faculty would get the list but not be able to use it.

Thankyou for your help, this was exactly what i needed