Easy way of adding back mail capabilities in sendmail when I add domains.

[Lists User]

Does anyone know of an easy way to update Sendmail to be a 
backup mail server for domains.  I keep adding domains and
I was wondering if there was an easy way of adding the necessary
domains in the sendmail configuration.

I know this is almost more of a Sendmail question, but I figure many
people of this post experience the same problems when they add
numerous domains.

Thanks.