1. ASP.NET - C#
 
<%@import namespace="System.Net"%>
<%@import namespace="System.Net.Mail"%>
<script language="C#" runat="server">
    protected void Page_Load(object sender, EventArgs e)
    {
        MailMessage m = new MailMessage();
        SmtpClient sc = new SmtpClient();
         try
            {
                m.Subject = "This is a Test Mail";
                m.IsBodyHtml = true;
                m.Body = "test gmail";
                sc.Host = "smtp.gmail.com";
                sc.Port = 587;
                       
                sc.EnableSsl = true;
                sc.Send(m);
                Response.Write("Email Send successfully");
            }
            catch (Exception ex)
            {
                Response.Write(ex.Message);
            }
    }
</script>
<html> 
<body> 
    <form runat="server"> 
        <asp:Label id="lblMessage" runat="server"></asp:Label> 
    </form> 
</body> 
</html>
 
2. ASP.NET - VB.NET
 
<%@ Page Language="VB" %> 
<%@ Import Namespace="System.Net.Mail" %> 
<script runat="server"> 
    Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) 
  
        Dim MailMsg As New MailMessage(New MailAddress(strFrom.Trim()), New MailAddress(strTo)) 
        MailMsg.BodyEncoding = Encoding.Default 
        MailMsg.Subject = "This is a test" 
        MailMsg.Body = "This is a sample message using SMTP authentication" 
        MailMsg.Priority = MailPriority.High 
        MailMsg.IsBodyHtml = True 
  
        Dim SmtpMail As New SmtpClient 
        Dim basicAuthenticationInfo
        SmtpMail.Host = "smtp.gmail.com"
        SmtpMail.Port=587
        SmtpMail.DeliveryMethod = SmtpDeliveryMethod.Network 
        SmtpMail.UseDefaultCredentials = False 
        SmtpMail.Credentials = new System.Net.NetworkCredential("[email protected]","*******") 
        SmtpMail.EnableSsl = true
        SmtpMail.Send(MailMsg) 
        lblMessage.Text = "Mail Sent"     
    End Sub 
</script> 
<html> 
<body> 
    <form runat="server"> 
        <asp:Label id="lblMessage" runat="server"></asp:Label> 
    </form> 
</body> 
</html>
 
3. PHP
 
<html>
<body>
<?php
include("class.phpmailer.php"); //you have to upload class files "class.phpmailer.php" and "class.smtp.php"
 
$mail = new PHPMailer();
 
$mail->IsSMTP();
$mail->SMTPAuth = true; 
$mail->SMTPSecure = "tls"; 
$mail->Host = "smtp.gmail.com"; 
$mail->Port = 587; 
$mail->Password = "********"; 
 
$mail->FromName = "demouser";
 
$mail->Subject = "This is the subject";
$mail->Body = "This is the body";
$mail->WordWrap = 50;
$mail->IsHTML(true); 
 
if(!$mail->Send()) {
echo "Mailer Error: " . $mail->ErrorInfo;
} else {
echo "Message has been sent";
}
?>
</body>
</html>