Smart URL

Hi,
I have a question about smart URL / opening a Landingpage with dynamic content.
As I understood it is possible to have a smartURL link such as mauticurl.tld/landingpage/?email=lead@example.de or other criteria…
But this link does not work if I entere it manually in the brower.
I want to archive following: I have a personalized landingpage and want to send a letter to some leads by traditional post (because of GDPR). In this letter I want to include the link to the specific URL or even QR Code - so to say a personal URL.
Does the smartURL not working like this or is there another way to have a personal URL functionality instead of smart URL?
Thanks
Jo
My Mautic version is:2.15.1