I am new to XML and we use PHP/MySQL for our site. I have a read through a few basic tutorials eg. writing DTD, Generate XML, Parse XML and display it.

We want to process data marked up as XML and sent to us via email or HTTP (preferably, as they would get a success or failure notification) or FTP. We have a jobs board and we wish enable our clients to send us data for multiple job postings to our site with the XML tags corresponding to the input fields on our job posting form.

Has anyone done this yet?

One of our clients say

You will need to tell us which URL you would like us to post the vacancies to, what port number we should use (usually 80) and whether or not you would like us to use HTTP or HTTPS.
I got a tip that for email submission we could create an email 'bot' that would accept mail to a specific address, verify it, XML parse the body of the email and then stick it into our MySQL db.

HTTP sounds easier than dismantling email messages.

Any pointers on where to start greatly appreciated!