how to use the isp's server to send mail

[Sanjay Arora]

We use qmail on RH Linux 6.2 and connect through multiple isps....use the
isp giving the best connection at the time...

My server makes a direct smtp connection & I want to configure it to use my
isp's server for forwarding the mail. Also, if this can be configure to
accomodate possibility of different isp's being dialled...it would be great.

Hope someone can give me some pointers.

With best regards.

Sanjay.