Mailing List Which...
 

I know alot of you have had experiance with mailing list scripts so please lend me your ear, [or rear if you prefer]

I need a script that can manage a list of approx 20-50k e-mails, has the ability to add a tickbox or combo list that says over 18 or not, mails out serverside and has high security that protects the list i.e someone wont be able to type in www.xxx.com/mailinglist/e-mails.txt and download the entire list.

Or is this a case of me getting some chinese indian to programme it for me?

Thanks for any and all help ^^