Specifying Sender Filtering Virus Settings

Procedure

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

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

   During each one-hour period that virus blocking is active, IMSS starts blocking IP addresses when more than 20% of the messages it receives contain viruses 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.