Problem When iHateSpam is installed in Outlook there are two problems:
iHateSpam does not correctly load if NEO is started before Outlook. See KB article T1062 for a description of this problem.
When both Outlook and NEO are closed, a hidden copy of Outlook continues to run and pick up mail. If you shut down Outlook and start it again, iHateSpam will no longer be functioning, and an invisible copy of Outlook will continue to run.
NEO uses an invisible copy of the Outlook Explorer to interact with Outlook. The instance of iHateSpam that is associated with this invisible copy does not close its interface to Outlook and therefore Outlook.exe keeps running.
Workaround Always have Outlook running when you start NEO, keep Outlook running while you are using NEO, and always close NEO before closing Outlook.
You can help ensure this by going to NEO Tools menu | Options and checking the option 'Start NEO when Outlook starts', then start Outlook in your normal way which in turn will automatically start NEO.
This problem is known to exist in iHateSpam version 3.0.323.