i've got some questions about how it works:
so ubuntu server comes with postfix installed.
if i want my php script to send a mail to lets say firstname.lastname@example.org, how does it work?
do i have to specify any ip to another MTA (my ISP's MTA?) in postfix's configuration file?
and if someone sends back, will it get to my ip? is it postfix that receives it? or has it to do with fetchmail?