Yes, uncomment the SMTP line. If you wish to modify the sendmail_from line to a valid email account, then you can uncomment that one as well.
Other advice: learn more about your server, read up on basic unix/linux stuff.
My own opinion: if you can't even answer a simple question such as 'What OS and version are you running?", then you should not be hosting, or at least not involved in trying to resolve problems on a server.
please guys stop this thread now. Do we really want someone who doesn't know what sendmail is and doesn't know what operating system they have - to be running an SMTP server? I for one am sick of all the spam I get from open relays and exploited servers.
jamesyeeoc (you hit the nail on the head)...
Hardjoko - you need to ask your system administrator these questions. If you don't have a system administrator - I'd would suggest that's your first step - you need to hire one!
Yes seriously I am that dumb. Why should I be smart if I am around smart people?
You should be smart enough to run your own server - mainly because.... you are trying to run your own server. The questions you've been asking are very very basic, unfortunatly if you don't know what you are doing your server will end up getting compromised and will be used to relay spam, relay viruses, start ssh attacks, ddos attacks etc. It will then affect other internet users too.