70 Configuring and Maintaining Your Server
4 To specify additional rules that are applied by the spam filter before
the SPF check is actually done by the mail server, type the rules you
need in the SPF local rules box.
We recommend that you add a rule for checking messages against the open
database of trusted senders, for example, 'include:spf.trusted-forwarder.org'. For
more information on SPF rules, visit http://www.ietf.org/internet-drafts/draft-schlitt-
spf-classic-02.txt.
5 To specify the rules that are applied to domains that do not publish
SPF records, type the rules into the SPF guess rules box.
Specifying a/24 mx/24 ptr gives good results for spam filters scoring Received-SPF
lines.
6 To specify an arbitrary error notice that is returned to the SMTP
sender when a message is rejected, type it into the SPF explanation text
box.
If no value is specified, the default text will be used as a notification.
7 To complete the setup, click OK.
Setting Up Server-wide Black and White Lists
To block mail from specific domains:
1 Click the Server shortcut in the navigation pane.
2 Click the Mail icon in the Services group.
3 Click the Black List tab.
4 Click the Add Domain icon.
5 Specify the name of the domain from which you do not want to
receive e-mail. For example, 'evilspammers.net'.
6 Click OK.
7 Repeat steps from 4 to 6 to add as many domains as required.
To allow mail reception from specific domains or networks:
1 Click the Server shortcut in the navigation pane.
2 Click the Mail icon in the Services group.
3 Click the White List tab.
4 Click the Add Network icon.
5 Specify an IP address or range of IP addresses from which mail must
always be accepted.
6 Click OK.
7 Repeat steps from 4 to 6 to add as many addresses as required.
