We regularly send out newsletters to certain recipients.
This months newsletter is offering a course, and requires some very simple feedback, a "yes" from people who may be interested, which of course requires details of who said yes. Now we could just put a link into the e-mail which takes the recipient to a website, where he/she writes his/her email in a form, but we want something simpler. We just want a link in the email that they can click on and that's it. But I can't think of a way to get that to work without it opening a mail program
However, I have seen email confirmations when registering with websites where a unique link is sent to a specific email address , and by clicking on that link, you've said you're you. This may be a solution?