I am not too sure about the encryption part, but what I recently implemented was Microsoft Office Live Communications Server 2005 which works well with SQL to log the conversations. As for encryption, I will look further into that. The "downside" with the switch is cost, and a slighty new UI. Instead of using MSN messenger, you will have to switch to Windows Messenger. They are VERY similar. You will need the latest version of Windows Messenger as well to support the SIP connection. It was fairly easy to setup as well. Just my 2cents.

As an added note, you said you have a 2k3 server fully patched...does this include SP1? If so, is Network Twister compatible with SP1? Do you need to make any changes in the SP1 firewall? Can't say I have used it before, but those are some things to look at. Best wishes.

Links for LiveServer and Windows Messenger:

http://snipurl.com/alo8

http://snipurl.com/b2n6


Edit: Looks like you CAN do encryption...sorry its late at night and I forgot about this feature....just came back from Alaska too :)

http://snipurl.com/f2p7