Looking for user management & newsletter plugin

Hello,

For one of my customers I need to achieve the following:

visitors should be able to subscribe to a newsletter
the webmaster should approve the subscription
the visitors should receive a password after approval so they can visit a password protected section of the website.
Anyone here knows a plugin with the above mentioned functionality? I’m proficient at PHP coding so I don’t mind to tinker with an existing plugin should not all functionality be possible.

Best regards
Geert