Generating XML & retrieving mail

For a college project I have to get 2 website to communicate with each other through sending e-mails containing XML. I have found a function to send mail and to parse XML, but no to retrieve mail or generate XML. I understand that PHP can be build with POP3 support but the default (Windows) version doesn't include support. So is there a place where I can download POP3 support as a module (or script)? And are there script to easily generate XML from a DTD or XML Schema definition? Or may be another solution? Thanks in advance, Sanjuro