I, like many others that have commented on this article, am unable to get php's "mail" function to work. I suspect it is some combination of masquarading, aliasing, host naming, blah.
Yet, mailing from php was my main objective in reading this article and following it's directions. All other things work, I can send and receive email from a number of accounts, some at my ISP and some hosted locally. And, it all integrates with Apple's mail app well.
A great follow up might be to help us get php mail working. Or, if anyone out there figures this one out, email me at one of my new email addresses: