Hi,
I am Nallakumar. I have more than 8 years of experience in Outlook Automation.
I would suggest you following solution instead of clicking on a link in the email,
1. We can create a Outlook AddIn using C#
2. That will create a button in the Outlook ribbon in the Read pane. That button will be labelled "Approve"
3. If Approve button is clicked, it will do the operations you have asked. We can even send that email also, if needed.
Thanks,
Nalla