You cannot use the MailAddress constructor for specifying multiple receipts, but you can to use the MailMessage object as showed below.
Using the MailMessage (not MailAddress) constructor:
var msg = new MailMessage("[email protected]", "[email protected], [email protected]");
another way is:
MailMessage mail = new MailMessage();
mail.To.Add("[email protected],[email protected],[email protected]");
another way is:
MailMessage msg = new MailMessage();
msg.To.Add("[email protected]");
msg.To.Add("[email protected]");
msg.To.Add("[email protected]");
msg.To.Add("[email protected]");