When using PHP's built-in mail function, does the "From" e-mail address have to be an actual email address or can it be a fake address you use to disguise the user's actual e-mail address? The reason I ask is because we're developing an online dating site, and I would prefer the emails that get sent out do not come from the user's actual email address. If I want to do something like this, do I need to set up a mailbox for each user that signs up on the site or can I just use an email address that doesn't actually have an e-mail box?