There is a special place in hell reserved for spammers. =( Spam volume has increased to the point where mail was coming in faster then spamassassin could go through it and we had backed up to 10k messages.
I've done some workarounds and tweaks to the spam parsing that I hope should improve the situation. All the old mail should now be caught up.
Spam volumes are high for all free email account providers. We have no control over how people use their dropzone.com email addresses and where they publish them. Best we can do is to try and manage the the spam best we can - unfortunately for us that requires processing power from our servers.
All should be resolved again now. Thank you for your patience.