diff --git a/account_advanced_protection_features/models/account_move.py b/account_advanced_protection_features/models/account_move.py
index 7c8f09b..417e5af 100644
--- a/account_advanced_protection_features/models/account_move.py
+++ b/account_advanced_protection_features/models/account_move.py
@@ -4,15 +4,12 @@ from odoo.exceptions import UserError
 class AccountMove(models.Model):
     _inherit = 'account.move'
 
-    sent_by_email = fields.Boolean()
-
     def button_draft(self):
-        res = super(AccountMove, self).button_draft()
-        if self.sent_by_email and self.journal_id.prevent_reset_to_draft_sent_invoice:
+        if self.is_move_sent and self.journal_id.prevent_reset_to_draft_sent_invoice:
             raise UserError(_(
                 "You cannot reset to draft this invoice because it has been sent by email."
             ))
-        return res
+        return super(AccountMove, self).button_draft()
 
     @api.ondelete(at_uninstall=False)
     def _check_posted(self):
diff --git a/account_advanced_protection_features/wizard/__init__.py b/account_advanced_protection_features/wizard/__init__.py
deleted file mode 100644
index 641fd38..0000000
--- a/account_advanced_protection_features/wizard/__init__.py
+++ /dev/null
@@ -1 +0,0 @@
-from . import account_invoice_send
\ No newline at end of file
diff --git a/account_advanced_protection_features/wizard/account_invoice_send.py b/account_advanced_protection_features/wizard/account_invoice_send.py
deleted file mode 100644
index 8724798..0000000
--- a/account_advanced_protection_features/wizard/account_invoice_send.py
+++ /dev/null
@@ -1,14 +0,0 @@
-# -*- coding: utf-8 -*-
-
-from odoo import api, fields, models, _
-
-
-class AccountInvoiceSend(models.TransientModel):
-    _inherit = 'account.invoice.send'
-
-    def send_and_print_action(self):
-        if self.model == "account.move":
-            move = self.env[self.model].browse(self.res_id)
-            move.sent_by_email = True
-
-        return super(AccountInvoiceSend, self).send_and_print_action()