Hi,
I'm having trouble extending the Newsletter class and rendering the data with the custom template used to send the emails.
Here is what I try to do:

class MyNewsletter extends Newsletter {
}

class MyNewsletter_Controller extends ContentController {
  function index(){
    return $this->renderWith('VernissageEmail');
  }
}

I also modified the file _config.php as advised on the post Custom data fields in newsletters

 Object::useCustomClass('Newsletter', 'MyNewsletter') 

The idea would be to put a link in the email to go to a webpage if there is trouble viewing the mail.

Hope someone can help me on this.

Thx,
ALex

If all you want is a custom template, just create one in your mysite/templates/email folder. Then you can pick which template to use in the admin section from a drop down.

Nope, I already have the template, and the newsletter is sent.
The idea is to have a webpage that shows the newsletter in the website.
Like a category "Sent Newsletter" in the public website, where you can find all newsletters