NIS2013 slows Outlook2007

Hello

When I open Outlook 2007 with NIS2015 and Settings turned ON Outlook2007 takes about 3 minutes to open

If in Settings/Antispam I turn AntiSpam to Off, Outlook 2007 opens within 5-10 seconds

I wish to use the antispam button.

How can I pevent NIS2015 from slowing my computer down please?

Many thanks

 

John