Can't send email .

 Hi , It 's the first time i write code for sending email but it doesn't work . When I click the Send button , it 's ok , no error  , but when i checked my inbox  (also bulk) , it  wasn't there .
 Here my code (i can't use source code tab , it keeping processing )

 Dim mailMessage As System.Net.Mail.MailMessage = New System.Net.Mail.MailMessage()

  
    mailMessage.From = New System.Net.Mail.MailAddress(txtFromAddress.Text.Trim()) 
    mailMessage.To.Add(New System.Net.Mail.MailAddress(txtToAddress.Text.Trim()))
 
    mailMessage.Priority = Net.Mail.MailPriority.High
 
    mailMessage.IsBodyHtml = False

  
    mailMessage.Subject = txtSubject.Text.Trim()
    mailMessage.Body = txtBody.Text.Trim()

    Dim ...