Отправить email и прикрепить файл

public static void CreateMessageWithAttachment(string server)
        {
            // Specify the file to be attached and sent. 
            // This example assumes that a file named Data.xls exists in the 
            // current working directory. 
            string file = "data.xls";
            // Create a message and set up the recipients.
            MailMessage message = new MailMessage(
               "jane@contoso.com",
               "ben@contoso.com",
               "Quarterly data report.",
               "See the attached spreadsheet.");
 
            // Create  the file attachment for this e-mail message.
            Attachment data = new Attachment(file, MediaTypeNames.Application.Octet);
            // Add time stamp information for the file.
            ContentDisposition disposition = data.ContentDisposition;
            disposition.CreationDate = System.IO.File.GetCreationTime(file);
            disposition.ModificationDate = System.IO.File.GetLastWriteTime(file);
            disposition.ReadDate = System.IO.File.GetLastAccessTime(file);
            // Add the file attachment to this e-mail message.
            message.Attachments.Add(data);
 
            //Send the message.
            SmtpClient client = new SmtpClient(server);
            // Add credentials if the SMTP server requires them.
            client.Credentials = CredentialCache.DefaultNetworkCredentials;
 
              client.Send(message);

MediaTypeNames.Application.Octet
ContentDisposition