Why do we use it? I have two offices with multiple folks assisting on various projects and files. It's too cumbersome to read 100+ emails a day. Also, phone calls back up, and intercom use is too disruptive. Thus, IM.
For many, IM has been through AOL or Yahoo. I wanted to have control over IM, have it occur in a closed environment, and I wanted it to be either cheap or free. I may have found the solution.
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24im.com is what we are trying. From their site, you will see the service provides:
Enterprise Instant Messaging
Presence Management
Project management
Department directories
Guest user access
Broadcast messaging
Group activity feed
Web-based or desktop access and
Role based administration
The messaging is encrypted. I like it a lot, and will test it fully for bugs and ease of use. Stay tuned.