Bind Sendmail to an IP address

[Aflatoon Aflatooni]

Hi,
I have a Freebsd 7.2 installation and using Sendmail for the SMTP service. This server has two public interfaces and different IP addresses.
I need to have sendmail configured so that the outbound emails are sent using a certain IP address (SPF rules).  I have tried the following without any success:

DAEMON_OPTIONS(`Addr=x.y.z.i')dnl
 
Any help or suggestions would be greatly appriciated.
 
Thanks