diff --git a/addons/mail/__init__.py b/addons/mail/__init__.py
index f3658293059..2ee7f9bb161 100644
--- a/addons/mail/__init__.py
+++ b/addons/mail/__init__.py
@@ -6,3 +6,6 @@ from . import tools
 from . import wizard
 from . import controllers
 from . import populate
+
+def _mail_post_init(env):
+    env['mail.alias.domain']._migrate_icp_to_domain()
diff --git a/addons/mail/__manifest__.py b/addons/mail/__manifest__.py
index 65eb3fedc72..c1447c57e9f 100644
--- a/addons/mail/__manifest__.py
+++ b/addons/mail/__manifest__.py
@@ -123,6 +123,7 @@ For more specific needs, you may also assign custom-defined actions
     ],
     'installable': True,
     'application': True,
+    'post_init_hook': '_mail_post_init',
     'assets': {
         'web._assets_primary_variables': [
             'mail/static/src/**/primary_variables.scss',
diff --git a/addons/mail/models/mail_alias_domain.py b/addons/mail/models/mail_alias_domain.py
index 81c17e9cbe3..6576318f4fa 100644
--- a/addons/mail/models/mail_alias_domain.py
+++ b/addons/mail/models/mail_alias_domain.py
@@ -4,6 +4,7 @@
 from odoo import api, exceptions, fields, models, _
 from odoo.addons.mail.models.mail_alias import dot_atom_text
 
+
 class AliasDomain(models.Model):
     """ Model alias domains, now company-specific. Alias domains are email
     domains used to receive emails through catchall and bounce aliases, as
@@ -174,3 +175,26 @@ class AliasDomain(models.Model):
                 config_values['default_from'], is_email=True
             )
         return config_values
+
+    @api.model
+    def _migrate_icp_to_domain(self):
+        """ Compatibility layer helping going from pre-v17 ICP to alias
+        domains. Mainly used when base mail configuration is done with 'base'
+        module only and 'mail' is installed afterwards: configuration should
+        not be lost (odoo.sh use case). """
+        Icp = self.env['ir.config_parameter'].sudo()
+        alias_domain = Icp.get_param('mail.catchall.domain')
+        if alias_domain:
+            existing = self.search([('name', '=', alias_domain)])
+            if existing:
+                return existing
+            bounce_alias = Icp.get_param('mail.bounce.alias')
+            catchall_alias = Icp.get_param('mail.catchall.alias')
+            default_from = Icp.get_param('mail.default.from')
+            return self.create({
+                'bounce_alias': bounce_alias or 'bounce',
+                'catchall_alias': catchall_alias or 'catchall',
+                'default_from': default_from or 'notifications',
+                'name': alias_domain,
+            })
+        return self.browse()
diff --git a/addons/mail/tests/test_mail_tools.py b/addons/mail/tests/test_mail_tools.py
index 02ef6ad2e50..66d58a86f61 100644
--- a/addons/mail/tests/test_mail_tools.py
+++ b/addons/mail/tests/test_mail_tools.py
@@ -150,3 +150,29 @@ class TestMailTools(MailCommon):
         self.user_employee.sudo().write({'email': '"Alfred Astaire" <%s>' % self.env.user.partner_id.email_normalized})
         found = self.env['res.partner']._mail_find_partner_from_emails([self.env.user.partner_id.email_formatted])
         self.assertEqual(found, [self.env.user.partner_id])
+
+
+@tagged('mail_tools', 'mail_init')
+class TestMailUtils(MailCommon):
+
+    def test_migrate_icp_to_domain(self):
+        """ Test ICP to alias domain migration """
+        self.env["ir.config_parameter"].set_param("mail.catchall.domain", "test.migration.com")
+        self.env["ir.config_parameter"].set_param("mail.bounce.alias", "migrate+bounce")
+        self.env["ir.config_parameter"].set_param("mail.catchall.alias", "migrate+catchall")
+        self.env["ir.config_parameter"].set_param("mail.default.from", "migrate+default_from")
+
+        existing = self.env["mail.alias.domain"].search([('name', '=', 'test.migration.com')])
+        self.assertFalse(existing)
+
+        new = self.env["mail.alias.domain"]._migrate_icp_to_domain()
+        self.assertEqual(new.name, "test.migration.com")
+        self.assertEqual(new.bounce_alias, "migrate+bounce")
+        self.assertEqual(new.catchall_alias, "migrate+catchall")
+        self.assertEqual(new.default_from, "migrate+default_from")
+
+        again = self.env["mail.alias.domain"]._migrate_icp_to_domain()
+        self.assertEqual(again.name, "test.migration.com")
+
+        existing = self.env["mail.alias.domain"].search([('name', '=', 'test.migration.com')])
+        self.assertEqual(len(existing), 1, 'Should not migrate twice')