it's OK
Regarding XMPP standart, room doesn't handle message id, so it will be null
Here is an example
sent message to room:
<message to="92_testroom2134@muc.chat.quickblox.com" id="366" type="groupchat"><body>Hello QuickBlox developer!</body></message>
received message from room:
<message xmlns="jabber:client" type="groupchat" from="92_testroom2134@muc.chat.quickblox.com/298" to="298-92@chat.quickblox.com/tigase-19912"><body>Hello QuickBlox developer!</body></message>
no ID in received message
ID only used in 1-1 chat
you can add custom parameters to Messages, just use http://www.igniterealtime.org/builds/smack/docs/3.2.2/javadoc/org/jivesoftware/smack/packet/Packet.html#setProperty(java.lang.String, java.lang.Object) to set
to get in listener