relay host in sendmail?

[jekillen]

Hello:
I am using Absolute BSD, Second Ed.
and am looking in the section on Sendmail.
I cannot find where to specify a relay host.
I have a hosts that originate mail to remote
recipients but use a mail hub (Postfix) on
another machine on local network to
relay this mail to the outside. It is not spam.
These messages will be used to verify web
client supplied e-mail addresses.
Thank you in advance;
Jeff K