The block period is the interval in which an email that has been initially blocked by the Greylist Anti-Spam filter, will continue to be blocked, in order to combat spammer attempts to circumvent this type of protection. The default value is of 15 minutes. Any emails re-sent after this period will be allowed through, provided it comes from the same source and is intended for the same destination.
To change the block period, the following registry key with the required value needs to be created.
- for 32bit operating system:
- for 64bit operating system:
- GFI MailEssentials 2012 or later:
If the Greylisting key does not exist, you have to create it first:
- Within the Greylisting key, create a new DWORD (32bit).
- Assign the RegValue: BlockPeriod. Value: (time in minutes)
Please ensure that the GFI MailEssentials services and Microsoft Exchange Transport service are restarted after changes were made to the above keys.