Newsletter with newsletters_posts changes when viewed in browser

Hi,

I'm creating newsletters that contains the last x post using the newsletters_posts shortcode. The newsletter also contains the "view in browser" link. However, when a subscriber clicks there after some days the browser view is different from the mail view since the shortcode is evaluated with the current date and, thus, contains recent posts that haven't been online when the newsletter was sent.
IMO the browser view and the mail view should be consistent all the time - no matter when it is viewed. Any chance to get this?

Thanks!