Prerequisites to make successful Exchange Granual update are as following:
1 : Member of the Domain Admin group and Local Admin Group if Exchange is a member server
2 : Create a Mailbox for Symantec, send a test email and oprn it in OWA to activate the Mailbox.
3 : Make sure that the Mailbox is not hidden from the Global Address List, and make sure there is not any other account with the same username and if it exists make sure to hide it from global address list.
4 : Add the account “symantec” as Exchange organization Administrator in Exchange Management Console.