Le transport a échoué dans sa connexion au serveur

Bonjour,
Je fais une application en vba qui envoie du courrier depuis une application, ça me donne

Erreur d'exécution - 2147220973 (80040213) Le transport a échoué dans sa connexion au serveur.

Veuillez aider si quelqu'un connaît la solution s'il vous plait.

Sub send_Gmail()

Dim NewMail As CDO.Message
Dim mailConfiguration As CDO.Configuration
Dim fields As Variant
Dim msConfigURL As String

On Error GoTo errHandle

Set NewMail = New CDO.Message
Set mailConfiguration = New CDO.Configuration

mailConfiguration.Load -1

Set fields = mailConfiguration.fields

With NewMail
.Subject = "bonjour"
.From = "********.fr"
.To = "*****@*****.fr"
.CC = ""
.BCC = ""
.TextBody = "This is a test email."
.AddAttachment "C:\Users\MonImageExcel.jpg"
End With


With fields
.Item("http://schemas.microsoft.com/cdo/configuration/urlproxyserver") = "proxy.server:8080"
.Item("http://schemas.microsoft.com/cdo/configuration/smtpusessl") = True
.Item("http://schemas.microsoft.com/cdo/configuration/smtpauthenticate") = 1

.Item("http://schemas.microsoft.com/cdo/configuration/smtpserver") = "smtp.gmail.com"
.Item("http://schemas.microsoft.com/cdo/configuration/smtpserverport") = 465
.Item("http://schemas.microsoft.com/cdo/configuration/sendusing") = 2

.Item("http://schemas.microsoft.com/cdo/configuration/sendusername") = "****@**.fr"
.Item("http://schemas.microsoft.com/cdo/configuration/sendpassword") = "******"

.Update

End With

NewMail.Configuration = mailConfiguration
NewMail.Send

MsgBox "E-Mail has been sent", vbInformation

exit_line:
'// Release object memory
Set NewMail = Nothing
Set mailConfiguration = Nothing

Exit Sub

errHandle:

MsgBox "Error: " & Err.Description, vbInformation

GoTo exit_line

End Sub