Imports System.Net.Mail

Public Class Form1
Dim SmtpServer As New SmtpClient()
Dim mail As New MailMessage()

Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
        sendEmail()
    End Sub

    Sub sendEmail()
        Try
            SmtpServer.Credentials = New Net.NetworkCredential("YOUREMAIL@yahoo.com", "PASSWORD")
            SmtpServer.Port = "587"
            SmtpServer.Host = "smtp.mail.yahoo.com"
            mail.From = New MailAddress("YOUREMAIL@yahoo.com")
            mail.To.Add("YOUREMAIL@yahoo.com")
            mail.Subject = "SUBJECT GOES HERE"
            mail.Body = "BODY OF EMAIL"
            SmtpServer.Send(mail)
        Catch ex As Exception
        End Try
    End Sub
End Class