In my case the code for extracting the email looks as follows:

string userEmail = e.FormData.GetValue("Email");
HttpCookie cookie = new HttpCookie(CookieEnabledVirtualPathProvider.PASS_COOKIE_NAME, userEmail);

So now in every request for a file I have the user’s email and then. when the user requests the file. I check

1) is the user a registered Episerver user – if so i don’t need to use the cookie as I prefer to know it’s our own user. Otherwise I extract the email from the cookie:

bool isLoggedIn = HttpContext.Current.Profile != null &&
    !HttpContext.Current.Profile.IsAnonymous;
bool isRegistered = HttpContext.Current.Request.Cookies.AllKeys.Contains(PASS_COOKIE_NAME);
string email = isRegistered
    ?
    HttpContext.Current.Request.Cookies[PASS_COOKIE_NAME].Value
    :
    (isLoggedIn ? HttpContext.Current.Profile.UserName : "unregistered");

now once I have the email – it’s stored in the database (in my case a simple Entity Framework context)

private void LogDownload (UnifiedFile file, string email)
{
    dbCookieProviderEntities context = new dbCookieProviderEntities();
    FileDownloadEntry logEntry = new FileDownloadEntry();
    logEntry.FilePath = file.VirtualPath;
    logEntry.DownloadDate = DateTime.Now;
    logEntry.UserEmail = email;
    context.AddToFileDownloadLog(logEntry);
    context.SaveChanges();
}

Once I have that I can provide nice statistics to the site owners regarding who downloaded what files. Which files have been downloaded how often and when.

If you’re interested, I can upload the full solution somewhere for you.

There are also issues when adding a file to the directory. The public override VirtualFile GetFile(string virtualPath) is executed also when adding files. So the form registration should not be redirected when in editmode. The same method will of course be exceuted when drag n drop of files are done. There are no methods to check this in EpiServer so after taking a look at the querystring this is my check for drag n drop; HttpContext.Current.Request["islastbits"] and this is for adding files in the File Manager; HttpContext.Current.Request["plugin"]. Could also check from inheritance from ActionWindow in the last one.

Else, this is working like a charm :D