I've followed the steps exactly for setting Delegate access in Outlook 2010 (Send on Behalf access was set up from Outlook, not the Server). The users cannot ‘Send on Behalf’ unless they select the sender’s name from the Global Address List. They have to click 'From' and then click 'Other Email Address...' to go to the GAL. If you try sending on behalf by selecting a name in the ‘From’ drop down box (because it was already sent form that address) it will fail with a non-deliverable error message. This even fails if the name is originally from the GAL. Our organization is using Exchange Server 2007 SP3 and the Domain Controllers are Windows Server 2008 R2 (Server 2003 Forrest Functional Level). All of the affected users with the Send on Behalf problem are using Outlook 2010. Would upgrading Office to SP1 or migrating to Exchange Server 2010 SP1 resolve this issue?
Perhaps on a related note; when adding a contact to Outlook from the Global Address Book, it will disappear from Outlook Contacts after about 10-15 seconds after clicking Save & Close to add it to the Contacts. The work around I found was to click File, Save-As, and save the VCF to my documents then double click the VCF file to add it to Outlook Contacts that way it doesn't disappear. Any help would be appreciated. Thanks. Please Advise.