diff --git a/utils/sendmail.py b/utils/sendmail.py
index 76dc5b88..0b10c3bd 100644
--- a/utils/sendmail.py
+++ b/utils/sendmail.py
@@ -18,7 +18,7 @@ def sendmail(emetteur, destinataires, objet, message, cc=[], more_headers={}, de
     mail["From"] = emetteur
     mail["To"] = u", ".join(destinataires)
     mail["Subject"] = objet
-    more_headers["X-Mailer"] = more_headers.get("X-Mailer", "/usr/scripts/utils/sendmail.py")
+    more_headers.setdefault("X-Mailer", "/usr/scripts/utils/sendmail.py")
     for k in more_headers.keys():
         mail[k] = more_headers[k]
     if cc != []: