make sure BOUNCE_PREFIX_FOR_REPLY_PHASE can't be used as directory name or for creating aliases on-the-fly

app/alias_utils.py

@@ -3,6 +3,7 @@ from typing import Optional
 
 from sqlalchemy.exc import IntegrityError, DataError
 
+from app.config import BOUNCE_PREFIX_FOR_REPLY_PHASE
 from app.email_utils import (
     get_email_domain_part,
     send_cannot_create_directory_alias,
@@ -29,6 +30,12 @@ from app.models import (
 
 def try_auto_create(address: str) -> Optional[Alias]:
     """Try to auto-create the alias using directory or catch-all domain"""
+    if address.startswith(f"{BOUNCE_PREFIX_FOR_REPLY_PHASE}+"):
+        LOG.exception(
+            "alias %s can't start with %s", address, BOUNCE_PREFIX_FOR_REPLY_PHASE
+        )
+        return None
+
     alias = try_auto_create_catch_all_domain(address)
     if not alias:
         alias = try_auto_create_directory(address)

app/dashboard/views/directory.py

@@ -3,7 +3,12 @@ from flask_login import login_required, current_user
 from flask_wtf import FlaskForm
 from wtforms import StringField, validators
 
-from app.config import EMAIL_DOMAIN, ALIAS_DOMAINS, MAX_NB_DIRECTORY
+from app.config import (
+    EMAIL_DOMAIN,
+    ALIAS_DOMAINS,
+    MAX_NB_DIRECTORY,
+    BOUNCE_PREFIX_FOR_REPLY_PHASE,
+)
 from app.dashboard.base import dashboard_bp
 from app.extensions import db
 from app.models import Directory, Mailbox, DirectoryMailbox
@@ -126,6 +131,7 @@ def directory():
                     "bounces",
                     "bounce",
                     "transactional",
+                    BOUNCE_PREFIX_FOR_REPLY_PHASE,
                 ):
                     flash(
                         "this directory name is reserved, please choose another name",

app/email_utils.py

@@ -370,7 +370,7 @@ def send_email_at_most_times(
     return True
 
 
-def get_email_local_part(address):
+def get_email_local_part(address) -> str:
     """
     Get the local part from email
     ab@cd.com -> ab