send email with the click of a button

Hi
I am trying to send smtp email when my form is submited to a list of emails that I retrieve from active directory. My question is do I have to format the email even though each section of the email will be already written in the code behind?
mailBody = mailBody.Replace("VAR1", _et._RequestID)
mailBody = mailBody.Replace("VAR2", _dd._dsUser.userFirstName)
mailBody = mailBody.Replace("VAR3", _et._DateSubmitted)

and how do add each email from active directory so far I have:
For Each r As DataRow In dt.Rows
mail.To.Add(r("ETEMAIL"))
Next

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