Web Forms :: Which Server Should Use Or Require To Send Mail

below is the coading to send email(just see the bold line). I just want to know which server i should use to send mail or which server is require to send mail.

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As_
System.EventArgs) Handles Button1.Click
Dim mailMessage As New MailMessage()
'creating an instance of the MailMessage class
mailMessage.From = "[URL]"
'senders email address
mailMessage.To = "[URL]"
'recipient's email address
mailMessage.Cc = "[URL]"
'email address of the Cc recipient
mailMessage.Bcc = "[URL]"
'email address of the Bcc recipient
mailMessage.Subject = "Hello"
'subject of the email message
mailMessage.BodyFormat = MailFormat.Text
'message text format. Can be text or html
mailMessage.Body = "This tutorial is sending email with an ASP.NET app."
'message body
mailMessage.Priority = MailPriority.Normal
'email priority. Can be low, normal or high
SmtpMail.SmtpServer = "[URL]"
'mail server used to send this email. modify this line based on your mail server
SmtpMail.Send(mailMessage)
'using the static method "Send" of the SmtpMail class to send the mail
Response.Write("Mail sent")
'message stating the mail is sent
End Sub