Adding another detail to the previous post (since this thread is specific to Outlook 2010):

In case of Outlook 2010 (32-bit), Norton AntiSpam does not import addresses from safe senders/ blocked senders but, it only imports those uncategorized addresses that are available in the outlook address book. So any address that you add to your Outlook's address book has to be added to Norton's Allowed List. And for those in Outlook Blocked Sender's list, you have to manually add them to Norton's Blocked List so as to let Outlook 2010 and Norton Antispam identify the spammers in unison. Thanks.