Get 404 when passing query string with @ symbol

[ciberperson]

I am trying to pass 3 parameters in a query string. One of those parameters is an email address. I Server.UrlEncode each parameter but then I get a PNF (404 error). If I take the @ symbol out of the email, all works fine.

Using c# on .NET 3.5. Here's my code behind:
protected void GetQyStr(object sender, EventArgs e)
{

string stringParam = "someone@yahoo.com";
string URLEncoded = Server.UrlEncode(stringParams);
string stringURL = "PassThruQS.aspx?f=name&l=worker&e=" + URLEncoded;
// Response.Redirect parameter
Page.Response.Redirect(stringURL);
}

I have tried this multiple ways and all work as long as I don't use @ in the email. What is the proper way to pass the email parameter, redirect to my new page and then extract the email address correctly from the querystring? Thanks for help on such a simple (!) issue.