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!
I've got the email being piped to the script, but I'm not sure how to transparently forward the email onwards... I've only ever used the script to upload a file.
Also, do I need to add something to the server to enable it to accept mail for a domain? I'm guessing there'll need to be an MX record for the domain but is there anything else that needs to be in place?