I have used ClamAV and Spamassassin for many years. I've had a less experience with Amavis (now amavisd-new), but I've decided to give it a try with a new mail server deployment I've been working on. As a reference for my install, I relied on the documentation provided by Amavis for integration with Postfix as well as a somewhat-outdated but still-relevant walkthrough published by CentOS . Prior to integration with amavisd, Postfix worked fine. Similarly, I had no issues with Spamassassin on its own. But once I finished my install of amavisd-new, things quickly went wrong. Attempting to send messages to accounts hosted on my email server resulted in the following chaing of errors in my maillog: Jan 13 18:17:34 hostname amavis[31578]: Net::Server: 2016/01/13-18:17:34 CONNECT TCP Peer: "[192.168.1.1]:40209" Local: "[127.0.0.1]:10024" Jan 13 18:17:34 hostname amavis[31578]: loaded base policy bank Jan 13 18:17:34 hostname amavis[31578]: lookup_ip_