Hey guys, I followed this guide (Perfect Server CentOS 6.4 | Apache) exactly, no more and no less. However I just got an email from my host saying that they have detected my server is acting as an open resolver. They asked that I update my DNS server to not be an open resolver. My questions are, how did this happen if I followed the guide exactly? Also how exactly do I fix this? Any help would be greatly appreciated. Thank you!