Steam get user's email address

Question

I am using an OpenId provider to let the user log into my site through steam. For when they register with additional information, I want to prefill their email address. However, I cannot seem to find a steam api for this. When I look at the claims, it just has steamid and friendly name. Then I thought to maybe use the webapi here:

http://api.steampowered.com/ISteamUser/GetPlayerSummaries/v0002/

However when I provide my info this is all I get back:

"response": {
    "players": [
        {
            "steamid": "99999999999999999",
            "communityvisibilitystate": 3,
            "profilestate": 1,
            "personaname": "Something",
            "lastlogoff": 1437554243,
            "profileurl": "http://steamcommunity.com/id/Something/",
            "avatar": "https://steamcdn-a.akamaihd.net/steamcommunity/public/images/avatars/a4/a4a54b1e0a8b0b3b85b87f9e38fde784b3ce322d.jpg",
            "avatarmedium": "https://steamcdn-a.akamaihd.net/steamcommunity/public/images/avatars/a4/a4a54b1e0a8b0b3b85b87f9e38fde784b3ce322d_medium.jpg",
            "avatarfull": "https://steamcdn-a.akamaihd.net/steamcommunity/public/images/avatars/a4/a4a54b1e0a8b0b3b85b87f9e38fde784b3ce322d_full.jpg",
            "personastate": 0,
            "realname": "tom",
            "primaryclanid": "103582791438339107",
            "timecreated": 1084138831,
            "personastateflags": 0,
            "loccountrycode": "US",
            "locstatecode": "FL",
            "loccityid": 1020
        }
    ]

}

Answer 1

Steam does not expose the email address.

That information is PII (personally identifiable information). As such, it is subject to various legal controls (depending on the jurisdiction).

Additionally, Steam would quickly lose customers if anyone with a Steam API key could retrieve email addresses for Steam customers and start spamming them.