SPAM: Prevent STMP Connection

[Mohammad Fattahian]

Hi,
I have Suse 9.0 and Lotus Domino 7.0.
When I opened Server Console, there are some unauthorized SMTP connections
to my server that tried to send e-mail.
I've configured my server configuration > Restriction Inbound / Outbound
SMTP Control.
How can I prevent some IP addresses to connect to my server?

Regards,

Mohammad Fattahian