Configuring SMTP Traffic Throttling Settings

Configure SMTP traffic throttling settings to block messages from a single IP address or sender email address for a certain time when the number of connections or messages reaches the specified threshold.

Note:
  • Disable SMTP traffic throttling when you deploy Deep Discovery Email Inspector as a non-edge MTA in your network.

  • When SMTP traffic volume is extremely high, Deep Discovery Email Inspector might not precisely block email messages based on the configuration due to the time delay between rule trigger and activation.

  • For information on how Deep Discovery Email Inspector blocks messages based on the Approved Senders and Blocked Senders lists, see Sender Filter Order of Evaluation.

  1. Go to Administration > Sender Filtering/Authentication > SMTP Traffic Throttling.
  2. Select one or both of the following options:
    • Enable SMTP traffic throttling based on sender IP addresses: Monitors traffic based on sender IP addresses

    • Enable SMTP traffic throttling based on sender email addresses: Monitors traffic based on sender email addresses

      Note:

      If you enable SMTP traffic throttling based on email addresses, Deep Discovery Email Inspector does not apply SMTP traffic throttling settings on traffic from sender email addresses in the Approved Senders list.

  3. Configure the following settings.
    Table 1.

    Field

    Description

    Maximum connections

    Type the maximum number of connections allowed for a single IP address.

    Maximum messages

    Type the maximum number of messages allowed from a single IP address or email address.

    Blocking duration

    Select the number of hours to block.

    Note:

    After blocking a sender for the specified time, Deep Discovery Email Inspector removes the sender from the Blocked Senders list.

  4. Click Save.

    To use the default settings, click Restore Default to discard your configuration.