diff --git a/addons/mail/models/mail_mail.py b/addons/mail/models/mail_mail.py
index f4ad3dea..3e12cc14 100644
--- a/addons/mail/models/mail_mail.py
+++ b/addons/mail/models/mail_mail.py
@@ -131,16 +131,19 @@ class MailMail(models.Model):
                                 messages to send (by default all 'outgoing'
                                 messages are sent).
         """
-        if not self.ids:
-            filters = ['&',
-                       ('state', '=', 'outgoing'),
-                       '|',
-                       ('scheduled_date', '<', datetime.datetime.now()),
-                       ('scheduled_date', '=', False)]
-            if 'filters' in self._context:
-                filters.extend(self._context['filters'])
-            # TODO: make limit configurable
-            ids = self.search(filters, limit=10000).ids
+        filters = ['&',
+                   ('state', '=', 'outgoing'),
+                   '|',
+                   ('scheduled_date', '<', datetime.datetime.now()),
+                   ('scheduled_date', '=', False)]
+        if 'filters' in self._context:
+            filters.extend(self._context['filters'])
+        # TODO: make limit configurable
+        filtered_ids = self.search(filters, limit=10000).ids
+        if not ids:
+            ids = filtered_ids
+        else:
+            ids = list(set(filtered_ids) & set(ids))
         res = None
         try:
             # auto-commit except in testing mode
diff --git a/addons/mail/models/mail_thread.py b/addons/mail/models/mail_thread.py
index 755172e7..2cf9e286 100644
--- a/addons/mail/models/mail_thread.py
+++ b/addons/mail/models/mail_thread.py
@@ -1732,6 +1732,8 @@ class MailThread(models.AbstractModel):
                 continue
             if isinstance(content, pycompat.text_type):
                 content = content.encode('utf-8')
+            elif content is None:
+                continue
             data_attach = {
                 'name': name,
                 'datas': base64.b64encode(content),
@@ -1757,7 +1759,7 @@ class MailThread(models.AbstractModel):
                     if not attachment:
                         attachment = fname_mapping.get(node.get('data-filename'), '')
                     if attachment:
-                        node.set('src', '/web/image/%s' % attachment.id)
+                        node.set('src', '/web/image/%s?access_token=%s' % (attachment.id, attachment.access_token))
                         postprocessed = True
             if postprocessed:
                 body = lxml.html.tostring(root, pretty_print=False, encoding='UTF-8')
diff --git a/addons/mail/wizard/invite_view.xml b/addons/mail/wizard/invite_view.xml
index 970ef84d..b72c1d85 100644
--- a/addons/mail/wizard/invite_view.xml
+++ b/addons/mail/wizard/invite_view.xml
@@ -20,7 +20,7 @@
                                 invisible="not context.get('mail_invite_follower_channel_only')"
                                 options="{'no_create': True}"/>
                         <field name="send_mail" invisible="context.get('mail_invite_follower_channel_only')"/>
-                        <field name="message" attrs="{'invisible': [('send_mail','!=',True)]}" options="{'style-inline': true}" class="test_message"/>
+                        <field name="message" attrs="{'invisible': [('send_mail','!=',True)]}" options="{'style-inline': true, 'no-attachment': true}" class="test_message"/>
                     </group>
                     <footer>
                         <button string="Add Followers"