Greylisting is a new tool in the fight against spam. What it does is temporarily block incoming mail from a sender. It returns the mail to the sender's mail server with a message saying try again later. The sending server must then retry sending the mail after the Block Period but before the Pass Period (see below for definitions of these values).
Greylisting is effective because spammers will not usually bother to attempt a second delivery, but legitimate e-mail servers will.
Greylisting is a very effective method of spam blocking that comes at a minimal price in terms of performance. Most of the actual processing that needs to be done for Greylisting takes place on the sender's server. It has been shown to block upwards of 95% of incoming spam simply because so many spammers don't use a standard mail server which will do automatic retries.
The biggest disadvantage of greylisting is the delay of legitimate e-mail from servers not yet verified. This is especially apparent when a server attempts verify a new user's identity by sending them a confirmation e-mail.
Some e-mail servers will not attempt to re-deliver e-mail or the re-delivery window is too short.
Once greylisting is activated we will give you the ability to override greylisting from all of your email accounts.
Your domain is now bypassing Greylisting. This option can be turned on again if you choose by following the same procedures. Be aware that by turning off this filtering and increasing the flow of spam through the shared server, ADVAIA may need to recommend other options (see below) to insure that this action does not disrupt other clients who are sharing mail services on the same server!