I have it set so any mail sent to *@pftq.com goes to me. There's one specific address that is getting spammed constantly and I'm wondering if I can set it so it forwards all addresses EXCEPT the spammed one. I can probably set up a mail account for the spammed address, but that would waste space on the site. I'd rather just have it not exist at all (and maybe have a "mailbox not found" returned to the sender )

If you have a catch-all email forwarder enabled, it will be pretty hard, if it's even possible.

You're using cPanel, right? If so, 10 or 11?

11. Ya go-figure... There should be a deny address feature.