Cool. We realized long ago that a well managed IT department in a large enough company (generally anything above 50 people) beats SaaS any day. SaaS is great for small numbers of users, but paying 100% of your license cost every single year is ludicrous. In addition, the loss of functionality and security puts you at a disadvantage from day 1. We firmly believe that the "managed" model is also inefficient (when we were smaller we switched Exchange from managed to inhouse and saved $30K/year instantly).
The problem is that these service providers (SaaS or Managed) tell customers that they'll need X number of employees to run a particular system themselves. What is not considered is the fact that one employee can manage a multitude of systems (we have 3 people managing 600 Linux based systems).
To realize more savings (over $120K), reduce complexity, increase features/performance, and improve reliability we have moved our worldwide users over to an inhouse instance of Zimbra. We have all that was cited (voicemail, IM, email) on a completely mixed client platform (35% Mac, 60% Windows, 5% Linux), with Blackberry Enterprise and ActiveSync support.
Thanks!
Rom