Wrap the send command in a try,catch block, this will prevent the app from "crashing". The error you are getting is probably in your email settings. I suggest searching the web for your exact problem, there are tons of info out. You mention you are still having problems, but this is your first post. I have successfully emailed using Gmail with no problems, here is the code and settings that I used:
Private Sub Button3_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim Email_Thread = New Thread(AddressOf Email)
Email_Thread.IsBackground = True
Email_Thread.Start()
End Sub
Private Sub Email()
Using mail As New MailMessage
Try
mail.From = New MailAddress("xxxxxxxxxxx@gmail.com") 'Your email
mail.To.Add(txt_Email_To.Text) ' Address to send to...
mail.Body = txt_Email_Body.Text
Catch
End Try
mail.Subject = txt_Email_Subject.Text
mail.IsBodyHtml = False
mail.Priority = MailPriority.Normal
Using SMTP As New SmtpClient
SMTP.EnableSsl = True
SMTP.Port = "587"
SMTP.Host = "smtp.gmail.com"
SMTP.UseDefaultCredentials = False
SMTP.DeliveryMethod = SmtpDeliveryMethod.Network
SMTP.Credentials = New Net.NetworkCredential("xxxxxxxx@gmail.com", "password") 'Enter your email and password
Try
SMTP.Send(mail)
Catch ex As Exception
MsgBox(ex.Message)
Return
End Try
Email_Success()
End Using
End Using
End Sub
Private Sub Email_Success()
MsgBox("Email has been sent successfully!")
End Sub
You obviously will need to replace "xxxxxxxx@gmail.com" with your email and "password" with your password.
