Passing Datatable Data As Attachement In Mail

In this blog, you will learn how to pass datatable data as attachement in Mail.

public string sendNetcoreEmail(string htmlString, string sub, string from, string to, string[] bccid, DataTable dt) {
    string ret = "true";
    try {
        MailMessage message = new MailMessage();
        SmtpClient smtp = new SmtpClient();
        message.From = new MailAddress(from, "sendername");
        if (bccid != null) {
            foreach(string bccMailID in bccid) {
                message.Bcc.Add(new MailAddress(bccMailID));
            }
        }
        message.To.Add(new MailAddress(to));
        message.Subject = sub;
        message.IsBodyHtml = true;
        message.Body = htmlString;
        var stream = new MemoryStream();
        var writer = new StreamWriter(stream);
        for (int i = 0; i < dt.Columns.Count; i++) {
            writer.Write(dt.Columns[i]);
            if (i < dt.Columns.Count - 1) {
                writer.Write(",");
            }
        }
        writer.Write(writer.NewLine);
        foreach(DataRow dr in dt.Rows) {
            for (int i = 0; i < dt.Columns.Count; i++) {
                if (!Convert.IsDBNull(dr[i])) {
                    string value = dr[i].ToString();
                    if (value.Contains(',')) {
                        value = String.Format("\"{0}\"", value);
                        writer.Write(value);
                    } else {
                        writer.Write(dr[i].ToString());
                    }
                }
                if (i < dt.Columns.Count - 1) {
                    writer.Write(",");
                }
            }
            writer.Write(writer.NewLine);
        } // using UTF-8 encoding by default //writer.WriteLine("Comma,Seperated,Values,...");
        writer.Flush();
        stream.Position = 0; // read from the start of what was written
        message.Attachments.Add(new Attachment(stream, "MyReferral.csv", "text/csv")); /**/
        smtp.Port = 587;
        smtp.Host = "smtpbp.falconide.com"; //for netcore host
        smtp.EnableSsl = false;
        smtp.UseDefaultCredentials = false;
        smtp.Credentials = new NetworkCredential("miraeassetcmdev", "59pXz*Nt5$AZSYL3");
        smtp.DeliveryMethod = SmtpDeliveryMethod.Network;
        smtp.Send(message);
    } catch (Exception ex) {
        ret = ex.Message.ToString();
    }
    return ret;
}