A user has created his own Secodary calendar in 2003.  it goes through our Exchange 2010 server to other users.  Other users are unable to voew this Secodary calendar.  HIs there a way he can share just this calendar?  Thanks

Hello,

You can choose to publicize a calendar of your group's events, save the calendar as a Web page, and then distribute the Uniform Resource Locator (URL).

Here is the article for your reference.

OL2002: How to Publish Your Outlook Calendar as a Web Page

http://support.microsoft.com/kb/292814

Or you can refer to the following thread to share your calendar.

http://answers.microsoft.com/en-us/office/forum/office_2007-outlook/accessing-shared-calendar-that-is-not-default/f6255df3-66cc-4e98-9925-5200e5e584c8