The email scanning function of NIS is blocking MS Outlook. Specifically if I try and check for new messages (F5) I get :
"Task 'mail.plus.net - Sending and recieving reported error (0x8004210A): the operation timed out waiting for a response from the recieving (POP) server.. etc"
With email scanning disabled temporarily Outlook works fine.
With email scanning enabled Outlook times out, BUT I can ping both the POP and SMTP servers.
The problem started when my subscription ran out (Aside: automatic renewal failed due to out of date CC info, I corrected that but annoyingly there there is no button to tell it to try again). When I opened NIS the day after the sub expired it was as if Symantec had taken revenge for my not renewing :-) NIS reported my PC wasn't secure. In particular it warned that email scanning wasn't enabled. It offered a fix button but when I pressed that it reported the fix failed. I manually renewed my subscription and everything then appeared normal except for email scanning not working.
I haven't yet tried uninstalling and reinstalling NIS, Is that the best thing to try first?