Find Facebook user (url to profile page) by known email address
Solution 1:
The definitive answer to this is from Facebook themselves. In post today at https://developers.facebook.com/bugs/335452696581712 a Facebook dev says
The ability to pass in an e-mail address into the "user" search type was
removed on July 10, 2013. This search type only returns results that match
a user's name (including alternate name).
So, alas, the simple answer is you can no longer search for users by their email address. This sucks, but that's Facebook's new rules.
Solution 2:
Simply use the graph API with this url format: https://graph.facebook.com/[email protected]&type=user&access_token=... You can easily create an application here and grab an access token for it here. I believe you get an estimated 600 requests per 600 seconds, although this isn't documented.
If you are doing this in bulk, you could use batch requests in batches of 20 email addresses. This may help with rate limits (I am not sure if you get 600 batch requests per 600 seconds or 600 individual requests).