The background info is this... I have a site where users can sign up for their own website. As well as having a subdomain address for their site (e.g. johnsmith.example.com) they could have their own domain (e.g. theirdomain.com) pointed to their site via the use of a CNAME record.
As well as the website, I'd like to offer users the ability to have email addresses @theirdomain.com. It would be a simple forwarder that would forward any mail sent to an address @theirdomain.com to the email address that I have on file for them.
As such, I'm hoping to avoid having to create mailboxes for each user, I just want to offer forwarding, no storage. Also, as the signup process is completely automated, I'd like this forwarding to be done through a PHP script so that I don't have to mess about with changing server config files every time a new user signs up.
I'm familiar with piping emails to a PHP script, but I don't have a clue where to start with this problem! Any help greatly appreciated!