I'm a new IT Specialist, and our CEO has a problem.  We use the online Exchange through Office365 and Outlook for Mac 2011, and his Calendar has over 8500 entries.  This causes extreme lag for him and his delegate.  In fact, I'm currently working offline, and can't even view the calendar entries due to lag.  He syncs this calendar with his Macbook Pro, IPad and IPhone, and his delegate also uses a Macbook Pro.

What he wants:  full access to all calendar entries (even those dating back to 2006), ability to read calendar across devices without debilitating lag.

Any help or ideas would be appreciated!

Thank you.