The Spam Mail Blocker can be configured to temporarily hold incoming mail items, which appear benign by all other tests, but are being sent from addresses that the local user has not received mail from previously nor have the source addresses been Global Allowed.
The Spam Mail Blocker lists these items in the Automatic Greylist and returns a "temporarily undeliverable" message to the sending server. The assumption in this process, is that a legitimate email server will wait an appropriate length of time and attempt delivery once again. When the mail is resent, a scan of the Grey List will legitimize the sender address, and the email will be forwarded to the local server for delivery to the target user.
This option is enabled or disabled within the Advanced Properties Page of the Spam Mail Blocker Object.
Management of this list is restricted to authorized administrators only, with the only option being to remove or delete an entry.
The TOOLS panel includes a database SEARCH utility to assist with reviewing entries within this table.
You may enter and search upon a full or partial Email address to locate specific records or display a list of similar entries from this table.
Automatic Greylist Table - online Help
Spam Mail Blocker Object - online Help