Greylisting is an anti-spam strategy that momentarily declines an email by imposing a temporary rejection on the sending email server. When a message comes in from an address or domain listed, it gets placed in a queue and will only be sent to the recipient if the sender tries to resend the message within a specified timeframe.
After a sender's legitimacy is confirmed, their address gets taken off the list, enabling subsequent messages from that address to traverse the filter smoothly without hindrance.
Greylisting detects incoming emails using triplets, encompassing three data elements: the IP address, the sender's, and the recipient's. By delaying unfamiliar triplets, Greylisting effectively filters out spam, granting valid emails a subsequent opportunity to traverse the system successfully.
Most Important Points:
Greylisting feature will only be available if your hosting company or system administrator turns on two things:
-> The "Configure Greylisting" option in WHM's Feature Manager (you can find it in WHM under Home, then Packages, and finally Feature Manager).
-> The "cPanel Greylisting Daemon" service in WHM's Service Manager (look for it in WHM under Home, then Service Configuration, and finally Service Manager).
To activate or deactivate the greylisting option, access your cPanel account:
Navigate to EMAIL and select Configure Greylisting.
Choose the domain for which you wish to activate/deactivate greylisting and modify the status by clicking the on/off icon.
Note: Deactivating this option could lead to more undesirable emails (spam).
To sum up, the Greylisting feature within cPanel is valuable for elevating your email interactions. Whether activated to counter spam or deactivated for uninterrupted communication, this functionality empowers you to tailor your email management according to your preferences and requirements.
If you want to enable or disable greylisting via WHM, check out this article.