diff --git a/addons/account/models/__init__.py b/addons/account/models/__init__.py
index f0bd1d9c573..811013f2094 100644
--- a/addons/account/models/__init__.py
+++ b/addons/account/models/__init__.py
@@ -31,3 +31,4 @@ from . import res_users
 from . import ir_actions_report
 from . import res_currency
 from . import res_bank
+from . import mail_thread
diff --git a/addons/account/models/mail_thread.py b/addons/account/models/mail_thread.py
new file mode 100644
index 00000000000..cf396c93e8e
--- /dev/null
+++ b/addons/account/models/mail_thread.py
@@ -0,0 +1,27 @@
+# -*- coding: utf-8 -*-
+# Part of Odoo. See LICENSE file for full copyright and licensing details.
+
+from odoo import models
+
+class MailThread(models.AbstractModel):
+    _inherit = 'mail.thread'
+
+    def _message_post_process_attachments(self, attachments, attachment_ids, message_values):
+        """ This method extension ensures that, when using the "Send & Print" feature, if the user
+        adds an attachment, the latter will be linked to the record. """
+        record = self.env.context.get('attached_to')
+        # link mail.compose.message attachments to attached_to
+        if record and record._name == 'account.move':
+            message_values['model'] = record._name
+            message_values['res_id'] = record.id
+        res = super()._message_post_process_attachments(attachments, attachment_ids, message_values)
+        # link account.invoice.send attachments to attached_to
+        model = message_values['model']
+        res_id = message_values['res_id']
+        att_ids = [att[1] for att in res.get('attachment_ids') or []]
+        if att_ids and model == 'account.move':
+            filtered_attachment_ids = self.env['ir.attachment'].sudo().browse(att_ids).filtered(
+                lambda a: a.res_model in ('account.invoice.send',) and a.create_uid.id == self._uid)
+            if filtered_attachment_ids:
+                filtered_attachment_ids.write({'res_model': model, 'res_id': res_id})
+        return res
diff --git a/addons/mail/wizard/mail_compose_message.py b/addons/mail/wizard/mail_compose_message.py
index 78bf51f7ec2..e1d790afcab 100644
--- a/addons/mail/wizard/mail_compose_message.py
+++ b/addons/mail/wizard/mail_compose_message.py
@@ -350,7 +350,7 @@ class MailComposer(models.TransientModel):
                     new_attach_id = self.env['ir.attachment'].browse(attach_id).copy({'res_model': self._name, 'res_id': self.id})
                     attachment_ids.append(new_attach_id.id)
                 attachment_ids.reverse()
-                mail_values['attachment_ids'] = self.env['mail.thread']._message_post_process_attachments(
+                mail_values['attachment_ids'] = self.env['mail.thread'].with_context(attached_to=record)._message_post_process_attachments(
                     mail_values.pop('attachments', []),
                     attachment_ids,
                     {'model': 'mail.message', 'res_id': 0}