@py sorry for the late reply! You may have already solved this, but perhaps this can help someone else who comes here after trying to reach krebs, or something similar.
I expect the reason why whitelisting krebsonsecurity.com in DNSBL did not solve the problem for you is because DNSBL is not what is blocking you, your IP blocking is. Go to your Reports / Alerts tab, and see where the block is happening.
I expect you may see that an attempt to hit krebsonsecurity.com with a browser results in:
[image: 1597776343628-krebsblock.png]
showing the block in the Deny section, and not in the DNSBL section.
If this is the case, instead of whitelisting the domain name in DNSBL Whitelist, try adding 130.211.45.45/32 to the IP / IPv4 Suppression list.
Works for me.
For the record, ipinfo.io confirms that krebsonsecurity.com is among the domain names hosted at 130.211.45.45.
[image: 1597776519325-krebsblockdomains.png]