Send E-mail with multiple Recipients

copy the following code.. its working for my gmail account 
in web.config
<system.net>
  
    <mailSettings>
      <smtp from="youremail@gmail.com">
        <network host="smtp.gmail.com" port="587" userName="youremail" password="xx" defaultCredentials="false"/>
      
      </smtp>
    </mailSettings>
  </system.net>
 
 
In code behind ( on button click)
 Dim smtp As New System.Net.Mail.SmtpClient()
        Dim smail As New System.Net.Mail.MailMessage
        smail.To.A ...