Certain users unable to send email internaly by typing adress ; only work when they use global catalog

got Office 2010 sp1 and win7  

Is there an Exchange Server involved?  You've posted in an Exchange Server 2013 forum, is that the version you're running?

Remove the outlook cache, Guess its the cache that's causing the problem, whereas when you pull the address from GAL it works fine.

refer to the article http://support.microsoft.com/default.aspx?kbid=287623