diff --git a/chatmaild/src/chatmaild/config.py b/chatmaild/src/chatmaild/config.py
index 332c1029..68d11f75 100644
--- a/chatmaild/src/chatmaild/config.py
+++ b/chatmaild/src/chatmaild/config.py
@@ -31,7 +31,7 @@ class Config:
         self.username_min_length = int(params["username_min_length"])
         self.username_max_length = int(params["username_max_length"])
         self.password_min_length = int(params["password_min_length"])
-        self.invite_token = params["invite_token"]
+        self.invite_token = params.get("invite_token", "")
         self.passthrough_senders = params["passthrough_senders"].split()
         self.passthrough_recipients = params["passthrough_recipients"].split()
         self.www_folder = params.get("www_folder", "")
diff --git a/chatmaild/src/chatmaild/doveauth.py b/chatmaild/src/chatmaild/doveauth.py
index 70589214..f1cc38fe 100644
--- a/chatmaild/src/chatmaild/doveauth.py
+++ b/chatmaild/src/chatmaild/doveauth.py
@@ -25,10 +25,15 @@ def is_allowed_to_create(config: Config, user, cleartext_password) -> bool:
     """Return True if user and password are admissable."""
     if os.path.exists(NOCREATE_FILE):
         if config.invite_token and config.invite_token not in cleartext_password:
-            logging.warning(f"blocked account creation because {NOCREATE_FILE!r} exists.")
+            logging.warning(
+                f"blocked account creation because {NOCREATE_FILE!r} exists."
+            )
             return False
 
-    if len(cleartext_password.replace(config.invite_token, "")) < config.password_min_length:
+    if (
+        len(cleartext_password.replace(config.invite_token, ""))
+        < config.password_min_length
+    ):
         logging.warning(
             "Password needs to be at least %s characters long",
             config.password_min_length,
diff --git a/chatmaild/src/chatmaild/newemail.py b/chatmaild/src/chatmaild/newemail.py
index cf483ff2..6ca39cba 100644
--- a/chatmaild/src/chatmaild/newemail.py
+++ b/chatmaild/src/chatmaild/newemail.py
@@ -21,9 +21,11 @@ def create_newemail_dict(config: Config):
         secrets.choice(ALPHANUMERIC_PUNCT)
         for _ in range(config.password_min_length + 3)
     )
-    redirect_uri = os.getenv("REQUEST_URI")
-    invite_token = redirect_uri[5:] if redirect_uri != "/new" else ""
-    return dict(email=f"{user}@{config.mail_domain}", password=f"{invite_token}{password}")
+    redirect_uri = os.getenv("REQUEST_URI", "/new")
+    invite_token = "" if redirect_uri == "/new" else redirect_uri[5:]
+    return dict(
+        email=f"{user}@{config.mail_domain}", password=f"{invite_token}{password}"
+    )
 
 
 def print_new_account():