Greylisting and Email Antispam

Greylisting is a form of email antispam, which dramatically reduces spam by making it wait to be received by the server. When an email message arrives at the SmarterMail server from an unfamiliar host or domain, the greylisting function refuses the message for a period of time (specified by the System Administrator). Legitimate message senders will retry to send the message a short time later, depending on their settings. Spam message senders tend to blast large volumes of email without repetition or electronic follow-up. The resend attempt made by a sender is a reasonable indicator of legitimacy. Mail that passes this test is released and delivered to the destination inboxes. Users who do not want to take advantage of this feature can disable Greylisting with a single setting change.