А если такой вариант?
http://www.semsoftware.com/
What is Gossip Corporate Messenger
Gossip Corporate Messenger ables you to create private and secure messaging network, based on client-server architecture. You can send and receive Message , Voice Message , File or Screen Shot or start multi-user Chat Sessions. Supports Windows 9x/NT/2000/XP.
General Server Features
Authentication - System access requires a valid User Name and Password.
No Internet Connection Required - Designed to use with LAN (Local Area Network) but you may also use over internet.
Offline Messaging - Messages that are sent to offline users stored by server and sent when they are first logged-in.
Message Logging - You may want to log messages between your users for auditing purposes even for all or a single account.
Department Management - You may define department base access rights for your users like forbiding File Transfer.
Hybrid Application - You may run your server as a Windows Service or Standard Application.
Multi-Threading - For maximum performance, stability and low memory consumption.
General Client Features
Contact List - Lets easy access to other Gossip Corporate Messenger users.
Online Alert - Checks if your contacts are on the Gossip Corporate Network in real time.
User Interface - Integrates smoothly into the desktop and works in the background, easily personalized.
User Search - You are able to search for a user with lots of conditions like User Name , First Name , Department , E-Mail vs.
Department Message - You can send message to whole department.
Message Archive - With Gossip Message Archive, you may centralize all of your incoming and outgoing messages.
Reminder - This feature allows you to write yourself reminders and preset the date and time you would like to receive them.
Multi Sessions - Allows you to send and receive Message , File or Screen Shot within same time.
Automatic Update - If a new update is available , it will automaticaly download and install from Gossip Corporate Server.
What is new in this version?
Gossip Corporate Server
Add:
Active Users tab for Manager.
Fix:
Server log files.
Fix:
Countless improvements and bugfixes.
Gossip Corporate Client
Add:
Proxy support.
Add:
Keep connection alive setting.
Add:
Auto Away and N/A mode settings.
Fix: Automatic server detection.
Fix: Compatibility issues with Windows 9x and NT.
Fix: Countless improvements and bugfixes.
System Requirements
A Pentium II CPU computer (at least).
64 MB of RAM (at least).
Windows 9x/NT/2000 or XP operating system.
Active network connection with TCP/IP protocol installed.