I would think running an open relay test would be step one. https://mxtoolbox.com/diagnostic.aspx
There are probably half a dozen online services that do this. Which brings me to my question: Is there an open relay test website that is considered the best? I have noticed some run multiple tests which I assume means different methods. Original Message From: wie...@porcupine.org Sent: October 16, 2020 3:27 PM To: postfix-users@postfix.org Reply-to: postfix-users@postfix.org Subject: Re: Mail server recently became an open relay Rich Wales: > Hi. My mail server (memoryalpha.richw.org), running Postfix 3.3.0, > recently started attracting open relay spam. I thought I had done all Why do you believe that your server is an open relay, as in, it will forward messages FROM spammers TO remote destinations. Wietse
