virtual_alias_maps = hash:/opt/csw/etc/postfix/virtual
    # vi /opt/csw/etc/postfix/virtual
    @exampledomain.com blackhole@localhost
    # /opt/csw/sbin/postmap hash:/opt/csw/etc/postfix/virtual
    # vi /etc/opt/csw/postfix/aliases
    blackhole: /dev/null
    # newaliases

    root@server:/etc/opt/csw/postfix> mailx test@exampledomain.com
    Subject: test

    .
    EOT
    root@server:/etc/opt/csw/postfix> grep example /var/log/syslog
    Oct 30 06:51:36 server.example.com postfix/local[26477]: [ID 197553 mail.info] C045F83C6: to=<blackhole@localhost.example.com>, orig_to=<test@exampledomain.com>, relay=local, delay=0.45, delays=0.18/0.27/0/0, dsn=2.0.0, status=sent (delivered to file: /dev/null)