Sending mail in asp.net using Exchange Server(smtp-outlook.office365.com) - asp.net

Question

We are working in Mailing system in asp.net,our client using Microsoft exchange server outlook.office365. We are getting this exception.
"System.Net.Mail.SmtpException: The operation has timed out " error .Please help us.
btn_click(){
try{SmtpClient smtp = new SmtpClient("smtp.outlook.office365.com");
smtp.Host = "outlook.office365.com";
smtp.Port = System.Convert.ToInt32("443");
System.Net.NetworkCredential cred = new System.Net.NetworkCredential("userid", "mypwd");
smtp.Credentials = cred;
smtp.DeliveryMethod = SmtpDeliveryMethod.Network;
smtp.UseDefaultCredentials = false;
smtp.EnableSsl = true;
smtp.TargetName = "STARTTLS/outlook.office365.com";
MailMessage msg = new MailMessage();
msg.From = new MailAddress("frommailid", "username");
msg.To.Add(new MailAddress("xxx#xxx.com"));
msg.Subject = "Test";
msg.Body = "Test mail ";
smtp.Timeout = 60000;
smtp.Send(msg);
}catch(exception ex)
{
throw ex;
}
}

Answer 1

Refer the below code snippet and try this out. It worked for me.
Remember: From field should be same email id which is used as an SMTP user. So in this example, xxx#blabla.onmicrosoft.com should be the From email id.
MailMessage mail = new MailMessage();
mail.To.Add(new MailAddress(ToField.Text));
mail.From = new MailAddress(FromField.Text); //From field should be same email id which is used as a SMTP user.
mail.Subject = "Email Subject";
mail.Body = "Message Body";
SmtpClient client = new SmtpClient();
client.UseDefaultCredentials = false;
client.Credentials = new System.Net.NetworkCredential("xxx#blabla.onmicrosoft.com", "Password");
client.Port = 587;//You can use Port 25 if 587 is blocked
client.Host = "smtp.office365.com";
client.DeliveryMethod = SmtpDeliveryMethod.Network;
client.EnableSsl = true;
client.TargetName = "STARTTLS/smtp.office365.com";
try {
client.Send(mail);
}
catch (Exception ex) {
ResponseLabel.Text = "Error:" + ex.Message;
}