diff --git a/account_invoice_subcontractor/__manifest__.py b/account_invoice_subcontractor/__manifest__.py
index 84751b1..d21626e 100644
--- a/account_invoice_subcontractor/__manifest__.py
+++ b/account_invoice_subcontractor/__manifest__.py
@@ -16,6 +16,7 @@
     ],
     "data": [
         "data/cron_data.xml",
+        "data/mail_data.xml",
         "security/security.xml",
         "security/ir.model.access.csv",
         "views/hr_employee_view.xml",
diff --git a/account_invoice_subcontractor/data/mail_data.xml b/account_invoice_subcontractor/data/mail_data.xml
new file mode 100644
index 0000000..5b20e94
--- /dev/null
+++ b/account_invoice_subcontractor/data/mail_data.xml
@@ -0,0 +1,25 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<odoo noupdate="1">
+
+    <record id="external_subcontractor_invoice_email_template" model="mail.template">
+        <field name="name">External subcontractor invoice template</field>
+        <field name="email_from">{{ (object.user_id.email or '') }}</field>
+        <field name="subject">Nouvelle facture sous traitance Akretion</field>
+        <field name="partner_to">{{ object.partner_id.id }}</field>
+        <field name="model_id" ref="account.model_account_move" />
+        <field name="auto_delete" eval="False" />
+        <field name="lang">{{ object.partner_id.lang }}</field>
+        <field name="report_template" ref="account.account_invoices" />
+        <field
+            name="body_html"
+        ><![CDATA[
+Une facture de sous traitance a été créée pour Akretion.
+Vous trouverez ci-joint le montant.
+Veuillez transmettre votre facture correspondante à l'adresse 'supplier@akretion.com' afin que nous puissions la valider et la payer une fois le paiement client effectué.
+Merci.
+
+Cordialement,
+        ]]></field>
+    </record>
+
+</odoo>
diff --git a/account_invoice_subcontractor/models/account_move.py b/account_invoice_subcontractor/models/account_move.py
index 6623df8..41a6248 100644
--- a/account_invoice_subcontractor/models/account_move.py
+++ b/account_invoice_subcontractor/models/account_move.py
@@ -36,6 +36,7 @@ class AccountMove(models.Model):
         readonly=True,
         prefetch=False,
     )
+    subcontractor_sent = fields.Boolean()
 
     @api.depends(
         "invoice_line_ids",
diff --git a/account_invoice_subcontractor/models/hr_employee.py b/account_invoice_subcontractor/models/hr_employee.py
index b7cfece..2ac3e41 100644
--- a/account_invoice_subcontractor/models/hr_employee.py
+++ b/account_invoice_subcontractor/models/hr_employee.py
@@ -24,6 +24,7 @@ def _get_subcontractor_type(self):
         required=True,
         default="internal",
     )
+    auto_generate_invoice = fields.Boolean(string="Création facture automatique")
 
     def _get_employee_invoice_partner(self):
         self.ensure_one()
diff --git a/account_invoice_subcontractor/models/subcontractor_work.py b/account_invoice_subcontractor/models/subcontractor_work.py
index 0ae81b4..e5e0a38 100644
--- a/account_invoice_subcontractor/models/subcontractor_work.py
+++ b/account_invoice_subcontractor/models/subcontractor_work.py
@@ -331,7 +331,9 @@ def _prepare_invoice_line(self, invoice):
     def _get_subcontractor_invoicing_group(self):
         groups = OrderedDict()
         for sub in self.sorted("invoice_date"):
-            if sub.subcontractor_type == "internal":
+            if sub.subcontractor_type == "internal" or self.env.context.get(
+                "invoice_create_cron"
+            ):
                 key = (sub.employee_id.id, sub.invoice_id.id)
             elif sub.subcontractor_type == "external":
                 key = (sub.employee_id.id, False)
@@ -383,11 +385,19 @@ def invoice_from_work(self):
 
     def _scheduler_action_subcontractor_invoice_create(self, days=7):
         date_filter = date.today() - timedelta(days=days)
+        # The order is used to start cron by external subcontractor because the user
+        # and company changes for internal subcontractors
         subcontractors = self.env["hr.employee"].search(
             [
+                "|",
+                "&",
                 ("subcontractor_type", "=", "internal"),
                 ("subcontractor_company_id", "!=", False),
-            ]
+                "&",
+                ("subcontractor_type", "=", "external"),
+                ("auto_generate_invoice", "=", True),
+            ],
+            order="subcontractor_type",
         )
         # Need to search on all subcontractor work
         # because of the filter on date invoice
@@ -395,29 +405,53 @@ def _scheduler_action_subcontractor_invoice_create(self, days=7):
             [
                 ("invoice_id.invoice_date", "<=", date_filter),
                 ("subcontractor_invoice_line_id", "=", False),
+                "|",
                 ("subcontractor_type", "=", "internal"),
+                "&",
+                ("subcontractor_type", "=", "external"),
+                ("employee_id.auto_generate_invoice", "=", True),
                 ("state", "in", ["posted", "paid"]),
             ],
         )
+        template = self.env.ref(
+            "account_invoice_subcontractor.external_subcontractor_invoice_email_template"
+        )
+        # Send validation email to old draft external subcontractor invoices
+        invoices = self.env["account.move"].search(
+            [
+                ("subcontractor_sent", "=", False),
+                ("partner_id", "in", subcontractors.user_id.partner_id.ids),
+                ("state", "=", "draft"),
+                ("create_date", "<=", date_filter),
+            ]
+        )
+        for draft_invoice in invoices:
+            template.send_mail(draft_invoice.id)
+            draft_invoice.subcontractor_sent = True
         for subcontractor in subcontractors:
-            dest_company = subcontractor.subcontractor_company_id
-            user = subcontractor.user_id
-            subcontractor_works = (
-                self.with_user(user)
-                .with_company(dest_company)
-                .search(
-                    [
-                        ("id", "in", all_works.ids),
-                        ("employee_id", "=", subcontractor.id),
-                    ],
-                )
+            if subcontractor.subcontractor_type == "internal":
+                dest_company = subcontractor.subcontractor_company_id
+                user = subcontractor.user_id
+                self = self.with_user(user).with_company(dest_company)
+            else:
+                # Used to group by invoice also for external in case of the cron
+                self = self.with_context(invoice_create_cron=True)
+            subcontractor_works = self.search(
+                [
+                    ("id", "in", all_works.ids),
+                    ("employee_id", "=", subcontractor.id),
+                ],
             )
             sub_ids = subcontractor_works.ids
             sub_name = subcontractor.name
             _logger.info(f"{sub_ids} lines found for subcontractor {sub_name}")
             invoices = subcontractor_works.invoice_from_work()
             for invoice in invoices:
-                invoice.action_post()
+                if subcontractor.subcontractor_type == "internal":
+                    invoice.action_post()
+                else:
+                    template.send_mail(invoice.id)
+                    invoice.subcontractor_sent = True
         #            if old_company:
         #                user.company_id = old_company.id
         return True
diff --git a/account_invoice_subcontractor/views/hr_employee_view.xml b/account_invoice_subcontractor/views/hr_employee_view.xml
index b2c7153..54b5501 100644
--- a/account_invoice_subcontractor/views/hr_employee_view.xml
+++ b/account_invoice_subcontractor/views/hr_employee_view.xml
@@ -14,6 +14,10 @@
                         name="subcontractor_company_id"
                         attrs="{'required': [('subcontractor_type', '=', 'internal'), ('active', '=', True)], 'invisible': [('subcontractor_type','!=', 'internal')]}"
                     />
+                    <field
+                        name="auto_generate_invoice"
+                        attrs="{'invisible': [('subcontractor_type','!=', 'external')]}"
+                    />
                 </group>
             </xpath>
         </field>