The presence plugin only ever returns forbidden:
The admin console is set to allow “anyone access”.
What’'s the problem?
The presence plugin will send this error message back if the user you’‘re requesting presence for isn’‘t on the local Wildfire server. There’'s no way to get presence information from other XMPP servers.
So, my guess is that your server name is “example.com” but that you’'re requesting presence for “im.server.com”.
Regards,
Matt