VB.net Amazon SES Sendmail Sample

gistfile1.vb

Dim sesClient As AmazonSimpleEmailServiceClient = New AmazonSimpleEmailServiceClient(strAccessID, strSecretAccessKey)
Dim sesBody As Model.Body = New Model.Body(New Model.Content(txtBody.Text))
Dim sesMsg As Model.Message = New Model.Message(New Model.Content(txtSubject.Text), sesBody)

Dim sesDest As Model.Destination = New Model.Destination()
sesDest.ToAddresses.Add(strToAddress)

Dim sesReq As Model.SendEmailRequest = New Model.SendEmailRequest(strFromAddress, sesDest, sesMsg)

sesClient.SendEmail(sesReq)

hi, I am getting error with this code
error THE SECURITY TOKEN INCLUDE IN THIS REQUEST IS INVALID
please please
CAN U HELLP ME?

CODE.
Private Sub cmdEnviarMail_Click(sender As Object, e As EventArgs) Handles cmdEnviarMail.Click
Try
Dim sesClient As AmazonSimpleEmailServiceClient = New AmazonSimpleEmailServiceClient(awsAccessKey, awsSecretKey, Amazon.RegionEndpoint.USEast2)

        Dim sesBody As Model.Body = New Model.Body(New Model.Content(txtBody.Text))
        Dim sesMsg As Model.Message = New Model.Message(New Model.Content(txtSubject.Text), sesBody)

        Dim sesDest As Model.Destination = New Model.Destination()
        sesDest.ToAddresses.Add(recipient)

        Dim sesReq As Model.SendEmailRequest = New Model.SendEmailRequest(source, sesDest, sesMsg)

        sesClient.SendEmail(sesReq)
        MsgBox("Email enviado con EXITO !!! ", MsgBoxStyle.Exclamation, "ITG Informa")
    Catch ex As Exception
        MsgBox("ERROR al enviar el email", MsgBoxStyle.Critical, "ITG Informa")
        MessageBox.Show(ex.Message)
    End Try




End Sub