How to allow an url with authentication? - asp.net

Question

I am sending an url to an email by buton click. When the email user is clicking the url he want to face login cardinals. I need to do the job without login cardinals.
Public Function SendMail(ByVal RuequestByEmpId As String, ByVal RuequestToEmpName As String, ByVal RuequestToEmpEmail As String) As Integer
Dim credential As New System.Net.NetworkCredential("joycseuiu#gmail.com", "something")
Dim msg As New System.Net.Mail.MailMessage()
Dim msgSubject As String = String.Empty
Dim strHeading As String = String.Empty
Dim EmployeeID As String = String.Empty
Dim Name As String = String.Empty
Dim Designation As String = String.Empty
Dim Email As String = String.Empty
Dim Department As String = String.Empty
Dim LeaveTYpe As String = String.Empty
Dim Reason As String = String.Empty
Dim LeaveAppID As String = String.Empty
Dim LeaveTo As String = String.Empty
Dim LeaveFrom As String = String.Empty
Dim Status As String = String.Empty
Dim i As Integer = 0
dsEmployeeInfoWithLeaveManagement.SelectParameters("EmployeeID").DefaultValue = RuequestByEmpId
dsEmployeeInfoWithLeaveManagement.DataBind()
dataview = dsEmployeeInfoWithLeaveManagement.Select(System.Web.UI.DataSourceSelectArguments.Empty)
Try
EmployeeID = dataview.Item(0).Row.Item("EmployeeID").ToString()
Name = dataview.Item(0).Row.Item("Name").ToString()
Designation = dataview.Item(0).Row.Item("Designation").ToString()
Department = dataview.Item(0).Row.Item("Department").ToString()
Email = dataview.Item(0).Row.Item("Email").ToString()
LeaveTYpe = dataview.Item(0).Row.Item("LeaveTYpe").ToString()
Reason = dataview.Item(0).Row.Item("Reason").ToString()
LeaveAppID = dataview.Item(0).Row.Item("LeaveAppID").ToString()
LeaveTo = dataview.Item(0).Row.Item("LeaveTo").ToString()
LeaveFrom = dataview.Item(0).Row.Item("LeaveFrom").ToString()
Status = dataview.Item(0).Row.Item("Status").ToString()
Catch ex As Exception
End Try
Dim SenderEmpName As String = "Joy Acharya"
Dim SenderEmpEmail As String = "joycseuiu#gmail.com"
msg.From = New System.Net.Mail.MailAddress(Email, Name)
msg.[To].Add(New System.Net.Mail.MailAddress(RuequestToEmpEmail, RuequestToEmpName))
Dim appSettings = ConfigurationManager.AppSettings
Dim result As String = appSettings("mailSender")
Dim strBody As New StringBuilder()
strBody.Append("<div>" & vbCr & vbLf & "<table>" & vbCr & vbLf & "<tr>" & vbCr & vbLf & "<td>")
msg.Subject = "Leave Application Approve"
strBody.Append("A request for leave has been submitted for your approval.")
strBody.Append("</td>" & vbCr & vbLf & "</tr>" & vbCr & vbLf & "<tr>" & vbCr & vbLf & " <td>" & vbCr & vbLf & "<span>Request By:</span>")
strBody.Append(Name)
strBody.Append("</td>" & vbCr & vbLf & "</tr>" & vbCr & vbLf & "<tr>" & vbCr & vbLf & " <td>" & vbCr & vbLf & "<span>ID:</span>")
strBody.Append(EmployeeID)
strBody.Append("</td>" & vbCr & vbLf & "</tr>" & vbCr & vbLf & "<tr>" & vbCr & vbLf & " <td>" & vbCr & vbLf & "<span>Designation:</span>")
strBody.Append(Designation)
strBody.Append("</td>" & vbCr & vbLf & "</tr>" & vbCr & vbLf & "<tr>" & vbCr & vbLf & " <td>" & vbCr & vbLf & "<span>Department:</span>")
strBody.Append(Department)
strBody.Append("</td>" & vbCr & vbLf & "</tr>" & vbCr & vbLf & "<tr>" & vbCr & vbLf & " <td>" & vbCr & vbLf & "<span>Leave Type:</span>")
strBody.Append(LeaveTYpe)
strBody.Append("</td>" & vbCr & vbLf & "</tr>" & vbCr & vbLf & "<tr>" & vbCr & vbLf & " <td>" & vbCr & vbLf & "<span>Purpose:</span>")
strBody.Append(Reason)
strBody.Append("</td>" & vbCr & vbLf & "</tr>" & vbCr & vbLf & "<tr>" & vbCr & vbLf & " <td>" & vbCr & vbLf & "<span>Leave To:</span>")
strBody.Append(LeaveTo)
strBody.Append("</td>" & vbCr & vbLf & "</tr>" & vbCr & vbLf & "<tr>" & vbCr & vbLf & " <td>" & vbCr & vbLf & "<span>Leave From:</span>")
strBody.Append(LeaveFrom)
strBody.Append("</td></tr>")
strBody.Append("</table>")
strBody.Append("<br />")
strBody.Append("<table>")
strBody.Append("<tr>")
strBody.Append("<td>")
strBody.Append(" " + "<b>Approve</b>" + "")
strBody.Append("</td>")
strBody.Append("<td>")
strBody.Append(" " + "<b>Reject</b>" + "")
strBody.Append("</td>")
strBody.Append("</tr>")
strBody.Append("<table>")
strBody.Append("</div>" & vbCr & vbLf & " <div>" & vbCr & vbLf & " Thank you" & vbCr & vbLf & " <br />")
strBody.Append("=======================================================================================")
strBody.Append("</div>")
msg.Body = strBody.ToString()
msg.IsBodyHtml = True
msg.Priority = System.Net.Mail.MailPriority.High
msg.Priority = System.Net.Mail.MailPriority.High
Dim c As New SmtpClient()
'----------------------------------
'Create the SMTP Client
c.Host = "smtp.gmail.com"
c.Credentials = credential
c.Port = 587
c.EnableSsl = True
Try
c.Send(msg)
Catch ex As Exception
End Try
Return i
End Function
When the email user clicking the Approve link, he has to face the
login cardinals.
I want that, email user will just click the link and he/she will be enable
to redirect the page.
How could i do that.
And thanks in advance.