ADSL and mail DNS

[lasa]

Hi,

I am facing a problem in configuring a Sendmail and DNS servers with a
ADSL line.

1).How can I config (edit the sendmail.cf file and other files like
hosts, network, reslove.conf, ifcfg-eth*) the mail server having with
ADSL (Dynamic IP) line to work with my other seperately loacted DNS
server(having static IP).

2).How can I config (edit the sendmail.cf file, Zone files and other
files like hosts, network, reslove.conf, ifcfg-eth*) the mail server
and DNS server having with ADSL (Dynamic IP) in same location itself.

Can sombody answer me in little bit expressive way please.

Thanks,
Lasantha Amarasinghe
Sri Lanka