Send Email from Outlook Error: Client was not authenticated to send anonymous mail during MAIL FROM

I want to send mail through outlook. i want to send my outlook mail id to another mail id. I had tried two methods but unable to find the solution. Can you suggest me a possible methods to recover my probs. for your reference i am send my code to you.

In 1st method, I am getting this Error

"The SMTP server requires a secure connection or the client was not authenticated. The server response was: 5.7.57 SMTP; Client was not authenticated to send anonymous mail during MAIL FROM [SG2PR06CA0239.apcprd06.prod.outlook.com]".

In 2nd method, I am getting this Error

"Failure sending mail."

    protected void btnmail_Click(object sender, EventArgs e)
    {
	//Outlook access 1st method
        SmtpClient smtpClient = new SmtpClient("smtp.office365.com", 587); //587
        smtpClient.UseDefaultCredentials = false;
        smtpClient.Credentials = new System.Net.NetworkCredential("outlook mail addr", "Password");

        smtpClient.DeliveryMethod = System.Net.Mail.SmtpDeliveryMethod.Network;
        smtpClient.EnableSsl = true;

        MailMessage mail = new MailMessage();
        mail.From = new MailAddress("From outlook mail addr", "CTMIS-no-reply");
        mail.To.Add(new MailAddress("To outlook mail addr"));
        //mail.CC.Add(new MailAddress("jcborlagdan@ymail.com"));
        smtpClient.Send(mail);

        //2nd MEthod
        SmtpClient sClient = new SmtpClient("domain-com.mail.protection.outlook.com");
        MailMessage message = new MailMessage();
        try
        {
            sClient.Port = 25;
            sClient.EnableSsl = true;
            sClient.Credentials = new NetworkCredential("outlook mail addr", "Password");
            message.Body = "Test";
            message.From = new MailAddress("From outlook mail addr");
            //message.To = new MailAddress("To outlook mail addr");
            message.Subject = "Test";
            //message.To = new MailAddress("software-trainee@blissgroup.com");
            message.CC.Add(new MailAddress("CC outlook mail addr"));
            sClient.UseDefaultCredentials = false;
            sClient.Send(message);
        }
        catch (Exception ex)
        {
            lblconfrim.Text = ex.Message;
        }
    }