Example 2

A domain administrator for bar.com wants to deny delivery from baz.com, except for a few trusted addresses.

+-------------+---------------+----------------+----------------------+--------------+--------+
| sender_name | sender_domain | src            | mta_fqdn             | dest_address | policy |
+-------------+---------------+----------------+----------------------+--------------+--------+
| *           | baz.com       | *              | *                    | *@bar.com    |      2 |
| trusted1    | baz.com       | *              | *                    | *@bar.com    |      1 |
| trusted2    | baz.com       | *              | *                    | *@bar.com    |      1 |
| trusted3    | baz.com       | *              | *                    | *@bar.com    |      1 |
+-------------+---------------+----------------+----------------------+--------------+--------+

The top rule restricts all mail from baz.com. The other three rules allows delivery from those specific addresses.