An email notification of type OPEN can be sent to anyone with an email address even if they are not a user.
When you first build the email notification there was a radio button at the top where you have a choice of open or recipient. You need to choose OPEN at that time. If for some reason that does not work for you then you need to put in a ticket to support to enable your realm to send external emails. If you do that then you can send an email which has the form in the email itself then the user would see the embedded report on that form. This assumes that the that embedded report is not so long that it won't fit on one page.