I've been reporting via SpamCop for years. I wrote an Outlook add-in that does my own brand of spam blocking, and includes a "Report to SpamCop" feature. It's been working for a very long time (I don't even remember how many years now).
Recently I'd been noticing that I'd often click on my "Report" button, send out the report, and never hear back. I'd just assumed some of my outgoing messages had been "eaten" somewhere in transit, and didn't fret about it. But this morning I did some experimentation and I've discovered the culprit.
Typically, my outgoing message will have my SpamCop submission address in the BCC line (which was the documented approach at some point). If the sending system was "known" (eg. aol.com), I'd manually add "abuse[at]aol.com" in the To line, but that was atypical.
I've discovered that if my message goes out with *only* the BCC, I'd never get a response back, and SpamCop's system would deny having received it. But if there's a 'To' address, then all is well, I'll get the SpamCop submission response minutes later.
My question(s): is this a known problem? Is it a deliberate action on SpamCop's part to ignore incoming Report messages without 'To' (or presumably CC) recipients?
I did poke through the FAQs and forum stickies, and I didn't see any notes on this.
Edit: It seems this isn't 100%, since I just sent a subsequent test message with no 'To', and *it* generated the response. So there's something else in play.