help me in mail server installation in ubuntu, postfix installation
 

please help me to install mail server in ubuntu 10.0,i have prefer postfix for this mail server and i tried to install through the formate that given in postfix's website but i cant install.

please help me the step needed for it.
The domain and dns are on the same machine,Is any problem related with it.

Any other configurations needed for postfix along with the domain name and dns.Is any database like mysql is needed.

You said following the instructions didn't work; but you didn't say why they didn't work. Without that, more advice is useless.