I had this same issue with my domain. there should be a link in the error message. My problem was because my IP address that I get from my ISP is a DHCP address. If yours is then your address automatically gets added to the Spamhaus list. It is easily corrected. Go to Spamhaus and go to the link in the middle of the page that says REMOVE IP ADDRESS. That page will give you more information on the problem and a way to fix it.
Additionally, if your IP Address is assigned to you in a pool of addresses it’s entirely possible that your server is being used to send spam– especially if you are removing it every day.
If your IP address comes from a DSL or cable provider, the first is a likely possibility. However, if you’ve been given a pool of addresses from Sprint, or some other T1/T3 carrier into your office you’ve likely got a spammer (or 500) using your server as a relay.
checking to see what list, (SBL, XBL, or PBL), your IP address is listed on will help determine if spammers are using your server as a relay