It's worth noting that dealing with email addresses like this affects other parts of the site. For example, I was signed up with Zappos with a blah+zappos@example.com email. Everything worked perfectly other than some of the links in the email, which didn't escape the '+', meaning that it was interpreted as a space. E.g.

  "https://example.com/unsubscribe?email=me+example@example.com"

vs.

  "https://example.com/unsubscribe?email=me%2Bexample@example.com"

[ On the plus side, Zappos was really responsive, and fixed the issue when I reported it. ]