Hello,
Currently, SmarterMails chat system is only internal to the domain and will not work cross-domain. The global address list ( GAL ) is built dynamically based on the users on the domain.
The only real workaround for this would be to export the GAL from one domain into a domain shared Contact list of another. The downside to this is it would need to be updated by the same process any time new data is introduced ( or removed )
I am going to create a Feature Request for this.
Thank you
Tony Scholz
System/Network Administrator
SmarterTools Inc.
www.smartertools.com