I have several email addresses forwarded to my acm.org address, which is forwarded to my spamcop.net address, which is forwarded to my io.com address.
I started to configure my spamcop account for mailhosts. I added my io.com account and everything looked ok. I added my acm.org account and the mailhosts configuration tool told me that it was too complex and suggested several hosts in the io.com domain which might not yet be registered. I registered them without incident, but the acm.org account was still too complex.
The other option was to request a waiver, which I did. It was granted, but I still don't understand what that means. Can anyone explain or point me to more detailed docs?