I am with you Keef of course, but I absolutely maintain that people should avoid any email system (which could mean avoiding a whole ISP) which does any kind of anti spam activity whatsoever.
It's more trouble than it is worth. I guarantee that my email sending is 100.000% secure and I never ever send out spam or anything infected. Yet, I estimate 1/3 of people I write to have my emails classified as spam, often with a "percentage probability" attached. The only basis on which this may be happening is (a) my IP or (b) my email address having been hijacked in the past, and neither of these are valid reasons for blacklisting me (basically, because they are innocent).
The passing of your emails via Spamcop, AIUI, does involve Spamcop doing some kind of filtering.
What I suggest is a decent futureproof solution which should always work, and is easy to manage.
One will never get ahead of spammers; that's impossible. All one can do is have a fairly unique address which they can't guess easily, and which one can change every few years or whatever.