I've sent a campaign to all of my contacts.  I'd to send a 2nd email to all the contacts that didn't respond yet. 

I have a list of the 600 contacts that responded. It's a CSV with email only as the field.  Is there a way to import that list just a suppression list so that I can send a campaign to my full contact list suppressing these 600 contacts/emails that already responded?

I see how I can use segments to do this on an individual basis, but I'd hope there'd be a way to easily import this list just as a suppression for this campaign rather than marking 600 contacts individually.

Thanks!