I am developing an application using UCMA 3.0 that will run as a service and send out periodic 'broadcasts' in the form of Instant Message calls. I have been using the book "Professional Unified Communications Development with Microsoft Lync Server 2010" and have everything provisioned fine and am able to establish an application endpoint.

I am stuck on two aspects though.

1) How to get a list of all users of Lync? Everything the UCMA can do is centered on a single user. For example it allows me to retrieve all contacts/groups present on a given users 'contact list' but does not provide any means to query for a list of available contacts that could be added to one of those contact lists. On the MSDN forum I found this post which leads me to think my best bet is simply to query AD directly.

2) What is the best way to actually send a broadcast style IM? My working premise is to attempt something like what I've found in this code example (specifically the public void SendIM() method).

So, get a list of recipients from AD, (looping on each on to check current presence?), and then use Automation to make the IM call for each recipient in the collection.

Does that make sense? Do I need to check presence of the recipient or do I just optimistically make the IM calls irregardless of their current presence status? Can anyone point me to some working code demonstrating sending an IM broadcast? You would think this is probably one of the most common use cases however the SDK samples do not cover it. Thanks in advance.