cPanel® Blog

Greylisting | cPanel Conference Session

Gain some insight into the effectiveness of Greylisting and learn how to use this feature in cPanel & WHM. Travis will provide even more spam-fighting techniques along the way.

Presenter: Travis Ellis


Equal parts prose, positivity, and passion, JR Miller is a web writer that likes using words to connect with people, enhance experiences, and solve problems. Approaching copywriting as both an art and a science, he believes that a good impression is one that stays with you after the browser window has closed.

  • Mike T

    Hey, I was the customer that fat-fingered and exempted a sixth of the internet from greylisting 🙂 But, I think my recommendation of the addition o rDNS/partial-rDNS matching in greylisting is paramount to making it easier to whitelist known good sources [usually large companies like Yahoo and such].

    I’m using RBL rejecting during SMTP time with BRBL and ZEN, as well as CPGrey and Pyzor+Razor2+DCC. All of that is quite automatic. In addition, a manual and monotonous task, is the adding of copious amounts of spammer IP space to /etc/spammerips (based upon my own personal belief of spammer IP space and the fact that they’ll never reform). I might add though that manual massaging of /etc/spammerips is something I rarely ever do now with CPGrey at work.

    CPGrey is doing a wonderful job considering it is in its infancy. My whitelist is quite significant though and does not rely upon anything that cPanel autopopulates into it. Fedex? They have a nice large chunk of IP space. The likelihood of intentional spam coming from that space is near zero — much easier to whitelist the whole swath of IP space. Same for many many large (non-email, non-hosting) companies and fed/state/mil agencies. /16s through /24s are very common in my whitelist.