Marketing campaign - which contacts NOT in campaign?

How can i determine which contacts are NOT getting campaign emails?

That depends on what you mean by ‘are NOT’. Are you asking if they are going through and getting sent them but are physically not receiving the email that was indeed sent or are you asking if they are actually getting to the point in your campaign where the email is sent in the first place?

asking if they are actually getting to the point in your campaign where the email is sent in the first place? i can see the report of the contacts which ARE getting the campaign, I want to run a report on which contacts are NOT getting the campaign.

So to do that you would first need to tag all those that completed that goal and then run a search for everyone that does not have that tag. The goal completion report will show you a list of all that have run through that goal/sequence. Select them and apply a tag to indicate this. Now go to your contact list and set the search criteria to show you everyone that does NOT have that tag.