Our organization would like to utilize the delegate features in Exchange and Outlook. Our organization is running Exchange Server 2010 and a mix of outlook versions. However when setting up delegates we are aware that the same version of Outlook must be used. When we attempt to setup delegates from within Outlook we get an error message that says " The Delegates settings were not saved correctly. Cannot Activate send-on-behalf-of list. You do not have sufficient permission to perform this operation on this object." We did go into our exchange server and verified that the self user had the "write personal information" checked as mentioned in another answer. Any help would be appreciated.