Specifying Sender Filtering Spam Settings

Procedure

1. Go to Sender Filtering → Rules.
   The Rules screen appears with 4 tabs, one for each type of threat.
2. Click the Spam tab.
   The Spam screen appears.
3. Select the Enable check box to enable blocking of spam.
4. Specify a value for the following:
   • Duration to monitor: The number of hours that IMSS monitors email traffic to see if the percentage of spam messages exceeds the threshold you set.
   • Rate (%): The maximum number of allowable messages with spam threats.
   • Total messages: The total number of spam messages out of which the threshold percentage is calculated.
   Consider the following example:

   Duration to monitor: 1 hour at a rate of 20 out of 100.

   During each one-hour period that spam blocking is active, IMSS starts blocking IP addresses when more than 20% of the messages it receives contain spam and the total number of messages exceeds 100.
5. Next to Triggering action, select one of the following:
   • Block temporarily: Block messages from the IP address temporarily and allow the upstream MTA to try again after the block duration ends.
   • Block permanently: Never allow another message from the IP address and do not allow the upstream MTA to try again.
6. Optional: If you select Block temporarily, specify the block duration.
7. Click Save.