[thelist] PHP Email Lists

[Rob Smith]

I'm trying to figure out a way to do mailing lists with PHP such that bad
email addresses are automatically removed from my database.

I know one or two of you have contacted me off list but I still want to do
this myself aside from a third party vendor. Its one of those "Build vs.
Buy" decisions.

Anywho, the typical emailing will have a plain text version sent out and an
unsubscribe link at the end, much like this current email. 

Now, take e-volt for example, do bad emails get removed automatically from
evolt's list? how is this accomplished without the user clicking the
unsubscribe link?

I'd really like to know how this is done in ASP and PHP if all possible,

TIA,

Rob Smith