Are there any third party MWI products for Exchange 2007 which are known to work with pbxnsip? I haven't found any which list pbxnsip as a supported IP PBX.
I have tried manually sending some SIP NOTIFY messages to pbxnsip with the relevant data, but it always responds with 404 not available. The SIP OPTIONS command does not list NOTIFY as supported. Is there a setting I have to enable somewhere in PBXnSIP for it to accept unsolicited notify messages from a SIP gateway (i.e. Exchange)?
As it doesn't appear to support these messages I am wondering if it is possible for a 3rd party product to achieve this?