private static async void SendEmail(LogFileType logType, SendLogJob job)
    {
        #region EMAIL_CONSTANTS
        string From = "abc@company.com";
        string To = "username@domain.com";
        #endregion

        try
        {
            MailAddress fromUsername = new MailAddress(From);
            MailAddress from = new MailAddress(From, "Auto Generated Mail", System.Text.Encoding.UTF8);
            MailAddress to = new MailAddress(To);
            const string fromPassword = "1234";

            var smtp = new SmtpClient
            {
                Host = "mail3.gridhost.co.uk",
                Port = 465,
                EnableSsl = true,
                DeliveryMethod = SmtpDeliveryMethod.Network,
                UseDefaultCredentials = false,
                Credentials = new NetworkCredential(fromUsername.Address, fromPassword)
            };



            var message = new MailMessage(from, to)
            {
                Subject = "Subject of the Email goes here",
                Body = "This is the EMail Body",
                IsBodyHtml=true,
                SubjectEncoding = System.Text.Encoding.UTF8,
                BodyEncoding = System.Text.Encoding.UTF8
            };

            smtp.SendCompleted += (s, e) =>
            {
                SendCompletedCallback(s, e);
                smtp.Dispose();
                message.Dispose();
            };
            MemoryStream stream = new MemoryStream(new byte[64000]);
            Attachment attachment = new Attachment(stream, logType + " File");
            message.Attachments.Add(attachment);
            smtp.SendAsync(message, message);

        }
        catch (Exception ex)
        {
            ex.Message.ToString();
        }

Syntax error, command unrecognized. The server response was:

at System.Net.Mail.SmtpConnection.ConnectAndHandshakeAsyncResult.End(IAsyncResult result) at System.Net.Mail.SmtpClient.ConnectCallback(IAsyncResult result)