✅(mailboxes) remove '+' from valid special caracters

We previously accepted '+' as a special caracter during mailbox creation.
We now remove it, as this caracter has a very special meaning and it wouldn't
make sense to create a mail using it.

src/backend/mailbox_manager/models.py

@@ -116,7 +116,7 @@ class Mailbox(BaseModel):
         max_length=150,
         null=False,
         blank=False,
-        validators=[validators.RegexValidator(regex="^[a-zA-Z0-9_.+-]+$")],
+        validators=[validators.RegexValidator(regex="^[a-zA-Z0-9_.-]+$")],
     )
     domain = models.ForeignKey(
         MailDomain,

src/backend/mailbox_manager/tests/test_models_mailboxes.py

@@ -38,13 +38,12 @@ def test_models_mailboxes__local_part_matches_expected_format():
     The local part should contain alpha-numeric caracters
     and a limited set of special caracters ("+", "-", ".", "_").
     """
-    factories.MailboxFactory(local_part="Marie-Jose.Perec+JO_2024")
+    # "-", ".", "_" are allowed
+    factories.MailboxFactory(local_part="Marie-Jose.Perec_2024")
 
-    # other special characters (such as "@" or "!") should raise a validation error
-    with pytest.raises(exceptions.ValidationError, match="Enter a valid value"):
-        factories.MailboxFactory(local_part="mariejo@unnecessarydomain.com")
-
-    for character in ["!", "$", "%"]:
+    # other special characters should raise a validation error
+    # "+" included, as this test is about mail creation
+    for character in ["+", "@", "!", "$", "%", " "]:
         with pytest.raises(exceptions.ValidationError, match="Enter a valid value"):
             factories.MailboxFactory(local_part=f"marie{character}jo")
 
@@ -186,7 +185,6 @@ def test_models_mailboxes__wrong_secret():
             payload = json.loads(rsps.calls[1].request.body)
             assert payload == {
                 "displayName": f"{mailbox.first_name} {mailbox.last_name}",
-                "email": f"{mailbox.local_part}@{domain.name}",
                 "givenName": mailbox.first_name,
                 "surName": mailbox.last_name,
             }
@@ -239,7 +237,6 @@ def test_models_mailboxes__create_mailbox_success(mock_info, mock_error):
         payload = json.loads(rsps.calls[1].request.body)
         assert payload == {
             "displayName": f"{mailbox.first_name} {mailbox.last_name}",
-            "email": f"{mailbox.local_part}@{domain.name}",
             "givenName": mailbox.first_name,
             "surName": mailbox.last_name,
         }