Spamcop Mail Delays

I use mail forwarding from my "published" address to my address 
at-spamcop-dot-net to my POP3 maibox. This has generally worked well, 
except for a short period a couple of years ago when mail flow was 
occasionally somewhat erratic. ISTR Spamcop was suffering some denial of 
service attacks at the time.

Lately I've started noticing delays, and things seem to be particularly 
bad, with one email (which has reached other recipients) still not 
having found its way into my POP3 box 90 minutes after it was sent. I've 
sent some test messages since, and have also looked at headers of 
messages that did get through, and the problem definitely seems to lie 
with Spamcop (cesmail).

Does anyone have any idea what's going on?

Any Spamcop deputies reading this?