GreyListing

The Greylisting method is very simple. It looks at only three pieces of information (which is referred to as a "triplet") about any particular mail delivery attempt:

1. The IP address of the host attempting the delivery.
2. The envelope sender address.
3. The envelope recipient address.

Greylisting follows one basic rule:
If the triplet has never been seen before, it refuses that particular delivery and any others that may come within a certain period of time with a temporary failure. Before applying greylisting procedure ITASM performs following filter checks on incoming emails:
Perform blacklist check. Blocks email if IP is blacklisted and skip greylisting.
Perform whistelist check. Allow email if IP is whitelisted and skip greylisting.
Apply header filter to the recipient of emails. If score encountered is -ve then email is allowed. If score is +ve email is blocked.
Sender history is maintained and if score assigned by sender history is -ve then greylisting will be bypassed.


GreyListing is also bypassed when the user is authenticated and the "Bypass authenticated users" option is enabled.

Other actions:

Enable GreyList: Uncheck this box if you do not want to use Grey List feature.

View Grey List Records

Manage Grey List
INITIAL DELAY (SECONDS): Initial delay is the blocking time period after which same email will be allowed to start smtp conversation. DELAY AGING TIME (SECONDS): This is the time window for email to go through if it retries within this time period.


WHITE LIST AGING TIME (SECONDS): This is the time period the white list record will remain valid.

UNIT CONVERSION:
1 min = 60 Seconds
1 hr = 3600 seconds
1 Day = 86400 seconds