diff --git a/addons/mail/models/mail_template.py b/addons/mail/models/mail_template.py
index cc07b375204..9de0c9bbb8e 100644
--- a/addons/mail/models/mail_template.py
+++ b/addons/mail/models/mail_template.py
@@ -484,10 +484,11 @@ class MailTemplate(models.Model):
         # templates: res_id -> template; template -> res_ids
         templates_to_res_ids = {}
         for res_id, template in res_ids_to_templates.iteritems():
-            templates_to_res_ids.setdefault(template, []).append(res_id)
+            templates_to_res_ids.setdefault((template, template.env.context.get('lang')), []).append(res_id)
 
         results = dict()
         for template, template_res_ids in templates_to_res_ids.iteritems():
+            template = template[0]
             Template = self.env['mail.template']
             # generate fields value for all res_ids linked to the current template
             if template.lang:
diff --git a/addons/mail/wizard/mail_compose_message.py b/addons/mail/wizard/mail_compose_message.py
index 4bc958684f9..64d3f2dfbf6 100644
--- a/addons/mail/wizard/mail_compose_message.py
+++ b/addons/mail/wizard/mail_compose_message.py
@@ -443,8 +443,8 @@ class MailComposer(models.TransientModel):
             multi_mode = False
             res_ids = [res_ids]
 
-        subjects = self.render_template(self.subject, self.model, res_ids)
-        bodies = self.render_template(self.body, self.model, res_ids, post_process=True)
+        subjects = self.render_template(self.subject, self.model, res_ids) if not self.template_id else False
+        bodies = self.render_template(self.body, self.model, res_ids, post_process=True) if not self.template_id else False
         emails_from = self.render_template(self.email_from, self.model, res_ids)
         replies_to = self.render_template(self.reply_to, self.model, res_ids)
         default_recipients = {}
@@ -454,8 +454,8 @@ class MailComposer(models.TransientModel):
         results = dict.fromkeys(res_ids, False)
         for res_id in res_ids:
             results[res_id] = {
-                'subject': subjects[res_id],
-                'body': bodies[res_id],
+                'subject': subjects[res_id] if subjects else False,
+                'body': bodies[res_id] if subjects else False,
                 'email_from': emails_from[res_id],
                 'reply_to': replies_to[res_id],
             }
@@ -465,7 +465,7 @@ class MailComposer(models.TransientModel):
         if self.template_id:
             template_values = self.generate_email_for_composer(
                 self.template_id.id, res_ids,
-                fields=['email_to', 'partner_to', 'email_cc', 'attachment_ids', 'mail_server_id'])
+                fields=['subject', 'body_html', 'email_to', 'partner_to', 'email_cc', 'attachment_ids', 'mail_server_id'])
         else:
             template_values = {}
 
@@ -475,6 +475,8 @@ class MailComposer(models.TransientModel):
                 results[res_id].pop('partner_ids')
                 results[res_id].pop('email_to')
                 results[res_id].pop('email_cc')
+                results[res_id].pop('subject')
+                results[res_id].pop('body')
                 # remove attachments from template values as they should not be rendered
                 template_values[res_id].pop('attachment_ids', None)
             else: