Email does not work- Please help!

I cannot get any email from this script. No activation emails are sent. No password requests can be sent. No email functionality at all. Is there a setting in a config file? I thought this script sent php mail. I need this to function as users do not get activation link and I want activation functionality. I now have that turned off. Not a good thing.
Please help!

vshare use php mail function, so if your mail server is configured properly with php, mails will work. If not, you need to check your mail server.