diff --git a/odex25_mobile/odex_web_app/models/mail_activity.py b/odex25_mobile/odex_web_app/models/mail_activity.py
index aceef2e6f..4e379d535 100644
--- a/odex25_mobile/odex_web_app/models/mail_activity.py
+++ b/odex25_mobile/odex_web_app/models/mail_activity.py
@@ -11,7 +11,9 @@ class MailActivity(models.Model):
         activity_ids = super(MailActivity, self).create(values)
         for activity_id in activity_ids:
             # Build message content
-            notification_body = re.sub(r'<[^>]+>', '', activity_id.note.replace('<br>', '\n'))
+            # Ensure activity_id.note is valid and avoid errors
+            note = activity_id.note or ''
+            notification_body = re.sub(r'<[^>]+>', '', note.replace('<br>', '\n'))
 
             # Send notifications
             employee_id = self.env['hr.employee'].sudo().search([('user_id', '=', activity_id.user_id.id)])
@@ -20,4 +22,4 @@ class MailActivity(models.Model):
                     "title": activity_id.summary or activity_id.create_uid.name,
                     "body": notification_body
                 })
-        return activity_ids
\ No newline at end of file
+        return activity_ids