👔(dimail) allow creation of "pending" mailboxes

Previously, mailbox creation was restricted to "enabled" domains.
We now allow users to create mailboxes on pending and failed domains.
Mailboxes thus created have the "pending" mailboxes status.

src/backend/mailbox_manager/tests/test_models_mailboxes.py

@@ -74,7 +74,7 @@ def test_models_mailboxes__domain_must_be_a_maildomain_instance():
 
 def test_models_mailboxes__domain_cannot_be_null():
     """The "domain" field should not be null."""
-    with pytest.raises(models.MailDomain.DoesNotExist, match="Mailbox has no domain."):
+    with pytest.raises(exceptions.ValidationError, match="This field cannot be null"):
         factories.MailboxFactory(domain=None)
 
 
@@ -93,44 +93,37 @@ def test_models_mailboxes__secondary_email_cannot_be_null():
         factories.MailboxFactory(secondary_email=None)
 
 
-def test_models_mailboxes__cannot_be_created_for_disabled_maildomain():
-    """Mailbox creation is allowed only for a domain enabled.
+@pytest.mark.parametrize(
+    "domain_status",
+    [
+        enums.MailDomainStatusChoices.PENDING,
+        enums.MailDomainStatusChoices.FAILED,
+    ],
+)
+def test_models_mailboxes__can_create_pending_mailboxes_on_non_enabled_domain(
+    domain_status,
+):
+    """Mailbox creation is allowed for a domain pending and failed.
+    A pending mailbox is created."""
+    mailbox = factories.MailboxFactory(
+        domain=factories.MailDomainFactory(status=domain_status)
+    )
+    assert mailbox.status == enums.MailboxStatusChoices.PENDING
+
+
+def test_models_mailboxes__cannot_create_mailboxes_on_disabled_domain():
+    """Mailbox creation is not allowed for a domain disabled.
     A disabled status for the mail domain raises an error."""
     with pytest.raises(
         exceptions.ValidationError,
-        match="You can create mailbox only for a domain enabled",
+        match="You can't create a mailbox for a disabled domain.",
     ):
         factories.MailboxFactory(
             domain=factories.MailDomainFactory(
                 status=enums.MailDomainStatusChoices.DISABLED
             )
         )
-
-
-def test_models_mailboxes__cannot_be_created_for_failed_maildomain():
-    """Mailbox creation is allowed only for a domain enabled.
-    A failed status for the mail domain raises an error."""
-    with pytest.raises(
-        exceptions.ValidationError,
-        match="You can create mailbox only for a domain enabled",
-    ):
-        factories.MailboxFactory(
-            domain=factories.MailDomainFactory(
-                status=enums.MailDomainStatusChoices.FAILED
-            )
-        )
-
-
-def test_models_mailboxes__cannot_be_created_for_pending_maildomain():
-    """Mailbox creation is allowed only for a domain enabled.
-    A pending status for the mail domain raises an error."""
-    with pytest.raises(
-        exceptions.ValidationError,
-        match="You can create mailbox only for a domain enabled",
-    ):
-        # MailDomainFactory initializes a mail domain with default values,
-        # so mail domain status is pending!
-        factories.MailboxFactory(domain=factories.MailDomainFactory())
+        assert not models.Mailbox.objects.exist()
 
 
 ### REACTING TO DIMAIL-API