Yes the Protector UTM appliance supports Anti Spam Grey Listing functionality.
This allows you to dramatically reduce the amount of spam you get.
You can also white list specific email addresses in the grey listing if you want.
The Extended Anti Spam gives full scanning of both incoming and outgoing mails.
To apply MCP Message Content Protection files
Anti Spam Grey Listing technology is a very effective technique in the ongoing battle against spam, virus, malware, phishing, worm, trojan attacks.
It will simple delay all incoming mails both valid and harmful mails for a few minutes.
Now a real mail server with legitimate mails will automatically recognize this delay and simple resend the mail so the user can receive it a few minutes later.
When the Protector Anti Spam Grey Listing module detects that the mail is being resend from the same target it will then be whitelist in the Grey Listing module.
It will still perform other checks but for the next time they sent to the grey listing it will go in without any delay.
It typically comes from programs or backdoors running on zombie hacked Windows workstations.
So those setup are not designed to get the mail back to resend it.
They are only designed to sending 1000 of mails in a very short period of time.
So by utilize the Anti Spam Grey Listing technique it is possible to throw away up to 80% of all unwanted and dangerous content mails.
This will dramatically reduce the load on the target mail server to improve performance and reduce the amount of spam, troajns, virus from even entering the network.
It is highly recommended to enable and use Anti Spam Greylisting.
So that it will not be effected at all by the Grey Listing
Example order emails where it is not possible to have a small delay but need the mails as fast as possible.
This makes Anti Spam Grey Listing safe to use for valid business mails.