I wanted to be able to send email from my blog when visitors placed comments on an entry. To do this I used the following code:

    Private Sub SendEmail()
        'from: http://www.4guysfromrolla.com/webtech/080801-1.shtml
        'Create an instance of the MailMessage class
        Dim objMM As New System.web.Mail.MailMessage

        'Set the properties
        objMM.To = "email@domain.com"
        objMM.From = "email@domain.com"

            'Send the email in text format
        objMM.BodyFormat = System.Web.Mail.MailFormat.Html
            '(to send HTML format, change MailFormat.Text to MailFormat.Html)

            'Set the priority - options are High, Low, and Normal
        objMM.Priority = System.Web.Mail.MailPriority.Normal

            'Set the subject
        objMM.Subject = "New Comment Posted"

            'Set the body - use VbCrLf to insert a carriage return
        objMM.Body = "The following comment was posted to your blog:" & txtBody.Text

        System.Web.Mail.SmtpMail.Send(objMM)
    End Sub

Check out the 4guys link for more properties etc.