Email subscription, where to start?

my company wants an email subscription form on the site that will allow them to send company/product news to the subscribers.

I know there are tutorials on the web that will teach me how to write on an XML file.

I would like the database to be made of XML and use ASP to save the email addresses from the form. My questions is how do I retrieve those email addresses from the XML file so that we can send the email from Outlook?

Would it be easier for my company to buy a software that will do this, and most importantly allow them to send emails that look like web pages, much like what Adobe would send.