I plan on upgrading our current exchange server from 2003 to 2010 and i wanted to know if it's a must to have all clients upgraded to 2010 as i know some of the PC's don't have the required hardware to run office 2010. Thanks Itai
No, it's not a must. Exchange 2010 will work with Outlook 2003, 2007 and 2010. And in the worst case, you can take advantage of Outlook Web Access and bypass Outlook on the client side. You'll have the best results with 2007 and 2010, though...