VB: Email sending with SMTP is failing - vb.net

Question

I'm adding an email sender in my app, so i used this:
Try
Dim oMail As New SmtpMail("TryIt")
Dim oSmtp As New SmtpClient()
oMail.From = "app-NHK#hotmail.com" ' From
oMail.To = "NHKomaiha#hotmail.com" ' To
oMail.Subject = Title.Text 'Title
oMail.TextBody = MsgTxt.Text 'Body
Dim oServer As New SmtpServer("smtp.live.com") ' SMTP server address
oServer.User = "app-NHK#hotmail.com" 'here i have written my app's email address made for sending the email from this form
oServer.Password = "thepassword" 'here i have put my app email password
oServer.ConnectType = SmtpConnectType.ConnectSSLAuto ' if SSL connection required
UseWaitCursor = True
Here done setting the main needed info
oSmtp.SendMail(oServer, oMail)
Sending...
UseWaitCursor = False
MessageBox.Show("E-Mail Sent Successfully", "Contact by E-Mail", MessageBoxButtons.OK, MessageBoxIcon.Information)
Main.BringToFront()
Main.Enabled = True
Close()
Error catching...
Catch ep As Exception
UseWaitCursor = False
MessageBox.Show("Error while sending E-Mail." & vbCrLf & vbCrLf & ep.Message, "Contact by E-Mail", MessageBoxButtons.OK, MessageBoxIcon.Error)
Dim closeerror = MessageBox.Show("Do you want to close?", "Contact by E-Mail", MessageBoxButtons.YesNo, MessageBoxIcon.Question)
If closeerror = DialogResult.Yes Then
Main.BringToFront()
Main.Enabled = True
Close()
End If
End Try
Is this code wrong? i used a lot of ways to send email but none worked
This time i got error: 550 5.3.4 Requested action not taken; To continue sending messages, please sign in to your account.

Answer 1

Modify and try this working example:
Imports System.Net.Mail
...
Try
Dim Email As New MailMessage()
Email.From = New MailAddress("abcdef#gmail.com")
Email.To.Add("other#provider.com")
Email.Subject = "Subject"
Email.IsBodyHtml = False 'or true if you want html
Email.Body = TextBox1.Text
Dim EmailClient As New SmtpClient("smtp.gmail.com", 587)
EmailClient.EnableSsl = True
EmailClient.Credentials = New Net.NetworkCredential("abcdef#gmail.com", "password")
EmailClient.Timeout = 7000
EmailClient.Send(Email)
Catch ex As SmtpException
MsgBox(ex.StatusCode & vbCrLf & ex.Message, vbCritical, "SMTP Error!")
End Try

Answer 2

Usually you need to specify port and authentication type in order to connect to an smtp server. It seems that smtp.live.com use SSL and port 465 (please verify this data).
So you can use SmtpClient.Port property to sets the port used for SMTP transactions and SmtpClient.EnableSSL to specify that SmtpClient uses Secure Sockets Layer (SSL) to encrypt the connection.