Is it possible to send a single IM message to a group of people via the openfire XMPP server?
Yes, in the openfire admin console, click on the “Sessions” tab across the top, then down the left side of that page you will see a “Send Message” button under the TOOLS heading. Type your message there and hit “send message”. Easy as pie! If you are wanting to target just a specific group, then use the “Broadcast” feature from the spark client, and then you can send a message to just certain groups!
Openfire supports XEP-0033 (“Extended Stanza Addressing”), which allows you to add multiple recipients for one stanza. You’d be able to do something like this:
<message to='multicast.jabber.org'> <addresses xmlns='http://jabber.org/protocol/address'> <address type='to' firstname.lastname@example.org/Work' desc='Joe Hildebrand'></address> <address type='cc' email@example.com/Home' desc='Jeremie Miller'></address> </addresses> <body>Hello, world!</body> </message><pre></pre>
Have a look at the XEP for more details: http://www.xmpp.org/extensions/xep-0033.html
And another option is to use the broadcast plugin.