Greylisting is used to prevent bulk e-mailers and SPAM bots from getting their email delivered. Greylisting is a temporary rejection of the message that forces the sending agent to resend the message at a later time. Legitimate senders will attempt a retry the message later while bots and spammers normally will not.
From Wikipedia: "Greylisting (or graylisting) is a method of defending email users against spam. A mail transfer agent (MTA) using greylisting will "temporarily reject" any email from a sender it does not recognize. If the mail is legitimate the originating server will, after a delay, try again and, if sufficient time has elapsed, the email will be accepted."
Greylisting is turned on by default on shared mail servers in our ongoing battle against spam. Bypassing the greylisting feature can be done at two different levels - the Domain level and the Individual level. To disable it, follow the instructions below.
Bypass at the Domain Level
You will need to contact support; one of our client support representatives will make this modification in your domain settings so that all mail boxes under that specific domain are bypassed automatically.
Bypass at the Individual Level
All email users have access to this with the SmarterMail web interface for their own account. This will allow bypass for just this mail account and not all accounts for the domain. If greylisting is on at the domain level and an individual chooses to bypass, all other accounts on the domain will remain greylisted.
How to disable greylisting in SmarterMail
Log in to Smartermail with an administrator account, go to SETTINGS > DOMAIN SETTINGS > USERS. Select the user and Under the "Users" tab, you will see a checkbox for "Disable Greylisting." Once checked, click Save. Click here for a step-by-step guide.
You may also log in to your mail account as a user:
Once logged into SmarterMail, go to SETTINGS > MY SETTINGS > ACCOUNT SETTINGS. Once on the Account Settings page, you should be under the "User" tab by default. If you are not under the "User" tab, be sure to select it. Under the "Users" tab, you will see a checkbox for "Disable Greylisting." Once checked, click Save.
Benefits of Greylisting:
- Spam Filter
- Default setting, requires no configuration
Negatives of Greylisting:
- First email between two contacts may be delayed, once the addresses are verified this process should be instantaneous.