Microsoft Exchange Server 2007 will reach end of support on April 11, 2017. For more information, see Resources to help you upgrade your Office 2007 servers and clients.
A global address list (GAL) is a directory that contains entries for every group, user, and contact within an organization's implementation of Microsoft Exchange Server.
Keep in mind that it will not be immediately available - the Offline Address Book (used by default to display GAL entries) will be updated the following morning (by default), at which point it will be available to clients.
Active directory has the correct info, and everything seems to be in place, our only issue is with the wrong name showing up in the shared Outlook calenders. I have frequently seen people change the CN (Common Name) of a user object, but not update the display Name attribute, or they do it the other way resulting in a user that is only half-way renamed.
To manage external contacts located in your GAL, follow the steps outlined below.