New Post: Generate Excel and Add As Email Attachment

using (MemoryStream memoryStream = new MemoryStream())
{
    MailMessage mailMessage = new MailMessage(smtpFrom, smtpTo);

    mailMessage.Subject = subject;
    mailMessage.Body = body;

    __memoryStream.Seek(0, SeekOrigin.Begin);__
    Attachment attachment = new Attachment(memoryStream, "<filename>.xlsx", "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
    mailMessage.Attachments.Add(attachment);

    SmtpClient smtpClient = new SmtpClient(smtpServer);
    smtpClient.Send(mailMessage);

    memoryStream.Close();
}