diff --git a/mbox2pdf.py b/mbox2pdf.py
index cc1a964..8d5e423 100755
--- a/mbox2pdf.py
+++ b/mbox2pdf.py
@@ -43,11 +43,11 @@ def extract_and_convert_email(message, output_file_base, i):
                         logging.warning(f"Format de date invalide: {date_header}")
                         output_file = os.path.join(output_file_base, f"email_{i}") # Nom par défaut si date invalide
                         date_simple = "<i>date inconnue</i>"
-                html_header = "<p><ul>"
+                html_header = "<div style=\"border: thick double black;\"><ul>"
                 html_header += f"<li>De : {from_header}</li>"
                 html_header += f"<li>&#192; : {to_header}</li>"
                 html_header += f"<li>Date : {date_simple}</li>"
-                html_header += "</ul><br /></p>"
+                html_header += "</ul><br /></div>"
                 # Conversion en PDF
                 try:
                     html_content = html_header + html_content