Your shopping cart is empty!
To whitelist means you're allowing, to blacklist means you're restricting. As the same suggests, greylisting is the middle ground. It's a technical security checkpoint for incmoing email.
Without getting too technical, let's say that greylisting is a temporary rejection of email from new domains. The basic concept relies on the idea that legitimate email has an intrinsic need to reach its destination. SPAM email just throws it all out there to see what sticks.
When you enable greylisting in your cPanel, you're telling the server to reject all email from new sources for x amount of minutes. Legitimate email servers will retry the send in a few minutes - often several times. SPAM servers won't put out that much effort. They see the email bounced and they move on to the next one.
Not really. You may need to wait a few minutes for an email that you probably didn't realize you were going to get anyway. I remember waiting two weeks for a letter from my pen pal in Hong Kong -- surely this shouldn't be a big deal! Well, we all know we're accustomed to the instant gratification that the internet provides.
The good news is that once an email is allowed through and not marked as SPAM, it will be allowed through down the line. So, your short wait is really a one-time event per address (email server).
Seriously - that's all!
Earth Girl Hosting servers are set to defer email for 5 minutes and we have a list of accepted hosts that will bypass the security check.
Yes, because SPAM can still come from legitimate hosts. Read my post on how to enable SPAM protection for the best email experience possible.