One issue I can think of is that this exposes your users to email phishing attacks by training them to click a URL in an email. I know Facebook has had this eff

One issue I can think of is that this exposes your users to email phishing attacks by training them to click a URL in an email. I know Facebook has had this effect on me. I have come close to clicking on phishing URLs because I get so many legit Facebook emails with links that I let my guard down.