diff --git a/odoo/addons/base/ir/ir_mail_server.py b/odoo/addons/base/ir/ir_mail_server.py
index 6bb287ca69b..2e936a74579 100644
--- a/odoo/addons/base/ir/ir_mail_server.py
+++ b/odoo/addons/base/ir/ir_mail_server.py
@@ -192,7 +192,7 @@ class IrMailServer(models.Model):
         """Returns a new SMTP connection to the give SMTP server, authenticated
            with ``user`` and ``password`` if provided, and encrypted as requested
            by the ``encryption`` parameter.
-        
+
            :param host: host or IP of SMTP server to connect to
            :param int port: SMTP port to connect to
            :param user: optional username to authenticate with
@@ -397,6 +397,7 @@ class IrMailServer(models.Model):
         email_to = message['To']
         email_cc = message['Cc']
         email_bcc = message['Bcc']
+        del message['Bcc']
 
         smtp_to_list = filter(None, tools.flatten(map(extract_rfc2822_addresses, [email_to, email_cc, email_bcc])))
         assert smtp_to_list, self.NO_VALID_RECIPIENT