Configure mail smarthost for PHP

[labsy]

Hi,

I am a bit outdated and confused, where and how is mail configured for all different PHP versions on server:

• - is it configured for PHP version in general, so all sites, which use this PHP version, have same settings?
• - or is it configured per web site?

So, I want all mail to go through my mail proxy, which can have 1 username for whole server. It will not use authentication, but will filter out spam. That's general config.

Beside that, I would like to setup separate mail smarthost to use customer's mail server and to have SMTP username/password authentication for all mail sent from this web site.

I just setup LiteSpeed with Apache back, no mail server specially configured on this server. It is web only server.
Any hints where and how to setup are appreciated.