Configuring Postfix Content Filtering

PureMessage will work with any version of Postfix that has content-filtering enabled. The Postfix content-filtering mechanism relies on the transfer of messages via SMTP to PureMessage. PureMessage can then modify and/or re-inject the message back into Postfix, quarantine the message, or take other actions based on the PureMessage policy.

To modify the Postfix content-filtering configuration:

  1. In the Background Services table on the Local Services tab, click SMTP (Postfix).

    The Postfix Status page is displayed.

  2. On the sidebar, click Content Filtering Configuration.

    The Postfix Content Filtering page is displayed.

  3. Change the text boxes in the Settings table as required.

    The text boxes are:

    • Host: The interface on which PureMessage listens for Postfix connections. If PureMessage is running on the same host as Postfix, this should be set to localhost. If not, specify the fully qualified hostname or IP address of the host where PureMessage is running. The value used here should correspond to the host part of the SMTP Talk Port (see "Editing the Basic Milter Settings" for more information).
    • Port: The port on which PureMessage listens for incoming Postfix connections. The default is 10025. The value used here should correspond to the port part of SMTP Talk Port (see "Editing the Basic Milter Settings" for more information).
    • Forward Host: The host through which PureMessage sends filtered mail. As with the Host option, this can be set to localhost if PureMessage and Postfix are running on the same host. The value used here should correspond to the host part of SMTP Listen Port (see "Editing the Basic Milter Settings" for more information).
    • Forward Port: The port on which PureMessage sends the message back to Postfix. The default is 10026. The value used here should correspond to the host part of SMTP Listen Port (see "Editing the Basic Milter Settings" for more information).
    • Concurrency: Determines how efficiently the system schedules filtering tasks. Higher concurrency values generally imply less latency in processing messages, but incur more scheduling overhead and higher memory consumption. This value should be increased in proportion to the number of CPUs on the system. A value of 3 x CPUs is recommended, with a minimum of 10.
  4. Click Save.
  5. Re-start the Postfix service for the changes to take effect.