I'm looking for a very simple way to add a newsletter signup to a client site. I searched google, but I don't know what's the simplest. Some folks recomended PHPList. It seems a little too complicated. Any have any good solutions to set up a newsletter subscription?

I dont know of any pre built code. It wouldnt be difficult to set up something simple with PHP and a database yourself. Just make a form to add users information to a database and some php code to send off emails.

I could take you a little while to build something from scratch but it may take just as long to find something and adapt it for your code.

Sorry i cant be of more help.