ASP.NET

Public Class WebMailBGEncoding
        Public [To] As String
        Public Subject As String
        Public Body As String

        Public Sub Send()
            If [To] = "" Then
                LogMassage = "Моля, въведете Вашия e-mail!"
            Else
                If Subject = "" Then
                    LogMassage = "Моля, въведете тема!"
                Else
                    If Body = "" Then
                        LogMassage = "Моля, въведете текст за тялото на e-mail!"
                    Else
                        ' System.Web.Mail.SmtpMail.SmtpServer is obsolete in 2.0
                        ' System.Net.Mail.SmtpClient is the alternate class for this in 2.0
                        Dim smtpClient As SmtpClient = New SmtpClient()
                        Dim message As New MailMessage
                        message.BodyEncoding = Encoding.UTF8
                        Try

                            Dim fromAddress As MailAddress = New MailAddress(FromEmail, FromName, Encoding.UTF8)

                            ' You can specify the host name or ipaddress of your server
                            ' Default in IIS will be localhost
                            smtpClient.Host = "localhost"

                            'Default port will be 25
                            smtpClient.Port = 25

                            'From address will be given as a MailAddress Object
                            message.From = "yourmail"

                            ' To address collection of MailAddress
                            message.To.Add([To])
                            message.Subject = Subject

                            ' CC and BCC optional
                            ' MailAddressCollection class is used to send the email to various users
                            ' You can specify Address as new MailAddress("admin1@yoursite.com")
                            'message.CC.Add("admin1@yoursite.com")

                            ' You can specify Address directly as string
                            '   message.Bcc.Add(New MailAddress(Bcc))

                            'Body can be Html or text format
                            'Specify true if it  is html message
                            message.IsBodyHtml = True

                            ' Message body content
                            message.Body = Body

                            ' Send SMTP mail
                            smtpClient.Send(message)

                        Catch ex As Exception
                            LogMassage = "Имаше проблем при изпращането на вашия email. Опитайте отново!"
                            'Catch ex As Exception
                            LogMassageDetails = CStr(Now()) + ", " + (("Следната грешка беше открита: " + ex.ToString()))
                            WriteAddRow(LogMassageDetails)
                            'check the InnerException
                            While Not (ex.InnerException Is Nothing)
                                LogMassageDetails += (("<br/>Вътрешна грешка беше открита: " + ex.InnerException.ToString()))
                                ex = ex.InnerException
                            End While
                        End Try
                    End If
                End If
            End If

        End Sub

    End Class

Ако Вашият майл сървър е защитен и изисква автентикация за да можете да изпращате имейли използвайте този код. 
Той е от вида mail.yourdomain.com. Порта е 25.
Задължително условие е този имейл от който ще изпращате да съществува във Вашия мейл сървър. Направено е с цел защита му от нежелано изпращане на СПАМ от други, чужди домейна и програми.

Пример

Web.config

  <system.net>
    <mailSettings>
      <smtp>
        <network
             host="mail.yourdomain.com"
             port="25"
             userName="yourmail@yourdomain.com"
             password="password" />
      </smtp>
    </mailSettings>
  </system.net>

Code
    dim FromAddress As String ="name@yourdomain.com" 
    dim ToAddress As String ="name@anydomain.com" 

    'Create the MailMessage instance
    Dim MyMailMessage As New MailMessage(FromAddress, ToAddress)

    ' Assign the MailMessage's properties
    MyMailMessage.Subject = Subject.Text
    MyMailMessage.Body = Body.Text
    MyMailMessage.IsBodyHtml = False

    ' Create the SmtpClient object
    Dim smtp As New SmtpClient

    ' Send the MailMessage (will use the Web.config settings)
    smtp.Send(MyMailMessage)