Bulk mail application, any tips ?

[harman]

I am about to start working on an email engine that sends bulk mail in html and normal text. I have looked at class.html_mime_mail.inc and class.phpmailer.php, Kindly suggest which one to use also any other suggestion and tips that you might think of.
P.s: I want to know the status of every mail i.e if it was recieved, returned, blocked etc.

[nemonoman]

The PHP manual has a pretty good usernote that explains sending text and html emails with and without embedded graphics.

There is no direct way to know the disposition of your email. Once they're go, they're gone. The sender will get a lot 'mail undeliverable' replies. You might be able to collect these and munge the headers for some data points.