Comfy Computing Ltd

Greylisting protection is an anti-spam measure we include for free on all incoming mail.

It's enabled by default and we recommend you leave it turned on.

It works by imposing a short delay on the first e-mail we receive from each sender: when our server receives the mail it asks the sending mail server to try again in 5 minutes. This is something which all genuine mail servers will do automatically, but which compromised PCs used for sending spam often ignore.

Once the first mail is successfully delivered we then remember that sender and let further mails through automatically, without any delay at all. And a sender only has to be approved once across all users whose mail we process — so you benefit from the greylisting we do for our other users, and if somebody mails you (or any other user on our system) at least once a month then he/she will never be subject to any further greylisting delays.

You'll only really notice the 5 minute delay if you are being sent an e-mail from somewhere new. The process is entirely automatic.

Note if you have a website that generates enquiry forms, you will not be able to use the greylisting facility.