diff --git a/chatmaild/src/chatmaild/dictproxy.py b/chatmaild/src/chatmaild/dictproxy.py
index dd4f9345..759b0173 100644
--- a/chatmaild/src/chatmaild/dictproxy.py
+++ b/chatmaild/src/chatmaild/dictproxy.py
@@ -21,19 +21,32 @@ def encrypt_password(password: str):
     return "{SHA512-CRYPT}" + passhash
 
 
-def check_password(password) -> bool:
-    """Check password policy"""
-    if len(password) < 10:
+def is_allowed_to_create(user, cleartext_password) -> bool:
+    """Return True if user and password are admissable."""
+    if os.path.exists(NOCREATE_FILE):
+        logging.warning(f"blocked account creation because {NOCREATE_FILE!r} exists.")
         return False
+
+    if len(cleartext_password) < 10:
+        logging.warning("Password needs to be at least 10 characters long")
+        return False
+
+    parts = user.split("@")
+    if len(parts) != 2:
+        logging.warning(f"user {user!r} is not a proper e-mail address")
+        return False
+    localpart, domain = parts
+
+    if domain == "nine.testrun.org":
+        # nine.testrun.org policy, username has to be exactly nine chars
+        if len(localpart) != 9:
+            logging.warning(f"localpart {localpart!r} has not exactly nine chars")
+            return False
+
     return True
 
 
 def create_user(db, user, encrypted_password):
-    if os.path.exists(NOCREATE_FILE):
-        logging.warning(
-            f"Didn't create account: {NOCREATE_FILE} exists. Delete the file to enable account creation."
-        )
-        return
     with db.write_transaction() as conn:
         conn.create_user(user, encrypted_password)
     return dict(
@@ -57,13 +70,13 @@ def lookup_userdb(db, user):
     return get_user_data(db, user)
 
 
-def lookup_passdb(db, user, password):
+def lookup_passdb(db, user, cleartext_password):
     userdata = get_user_data(db, user)
     if not userdata:
-        if not check_password(password):
-            logging.warning("Attempt to create an account with a weak password.")
+        if not is_allowed_to_create(user, cleartext_password):
             return
-        return create_user(db, user, encrypt_password(password))
+        encrypted_password = encrypt_password(cleartext_password)
+        userdata = create_user(db=db, user=user, encrypted_password=encrypted_password)
     userdata["password"] = userdata["password"].strip()
     return userdata
 
@@ -87,7 +100,7 @@ def handle_dovecot_request(msg, db, mail_domain):
                     reply_command = "N"
             elif type == "passdb":
                 if user.endswith(f"@{mail_domain}"):
-                    res = lookup_passdb(db, user, password=args[0])
+                    res = lookup_passdb(db, user, cleartext_password=args[0])
                 if res:
                     reply_command = "O"
                 else:
diff --git a/tests/chatmaild/test_dictproxy.py b/tests/chatmaild/test_dictproxy.py
index 77150ce1..0eec33cb 100644
--- a/tests/chatmaild/test_dictproxy.py
+++ b/tests/chatmaild/test_dictproxy.py
@@ -1,9 +1,10 @@
 import os
+import json
 
 import pytest
 
 import chatmaild.dictproxy
-from chatmaild.dictproxy import get_user_data, lookup_passdb
+from chatmaild.dictproxy import get_user_data, lookup_passdb, handle_dovecot_request
 from chatmaild.database import Database, DBError
 
 
@@ -14,13 +15,13 @@ def db(tmpdir):
     return Database(db_path)
 
 
+
 def test_basic(db):
-    chatmaild.dictproxy.NOCREATE_FILE = "/tmp/nocreate"
-    if os.path.exists(chatmaild.dictproxy.NOCREATE_FILE):
-        os.remove(chatmaild.dictproxy.NOCREATE_FILE)
     lookup_passdb(db, "link2xt@c1.testrun.org", "Pieg9aeToe3eghuthe5u")
     data = get_user_data(db, "link2xt@c1.testrun.org")
     assert data
+    data2 = lookup_passdb(db, "link2xt@c1.testrun.org", "Pieg9aeToe3eghuthe5u")
+    assert data == data2
 
 
 def test_dont_overwrite_password_on_wrong_login(db):
@@ -32,14 +33,12 @@ def test_dont_overwrite_password_on_wrong_login(db):
     assert res["password"] == res2["password"]
 
 
-def test_nocreate_file(db):
-    chatmaild.dictproxy.NOCREATE_FILE = "/tmp/nocreate"
-    with open(chatmaild.dictproxy.NOCREATE_FILE, "w+") as f:
-        f.write("")
-    assert os.path.exists(chatmaild.dictproxy.NOCREATE_FILE)
+def test_nocreate_file(db, monkeypatch, tmpdir):
+    p = tmpdir.join("nocreate")
+    p.write("")
+    monkeypatch.setattr(chatmaild.dictproxy, "NOCREATE_FILE", str(p))
     lookup_passdb(db, "newuser1@something.org", "zequ0Aimuchoodaechik")
     assert not get_user_data(db, "newuser1@something.org")
-    os.remove(chatmaild.dictproxy.NOCREATE_FILE)
 
 
 def test_db_version(db):
@@ -51,3 +50,15 @@ def test_too_high_db_version(db):
         conn.execute("PRAGMA user_version=%s;" % (999,))
     with pytest.raises(DBError):
         db.ensure_tables()
+
+
+def test_handle_dovecot_request(db):
+    msg = ('Lshared/passdb/laksjdlaksjdlaksjdlk12j3l1k2j3123/'
+           'some42@c3.testrun.org\tsome42@c3.testrun.org')
+    res = handle_dovecot_request(msg, db, "c3.testrun.org")
+    assert res
+    assert res[0] == "O" and res.endswith("\n")
+    userdata = json.loads(res[1:].strip())
+    assert userdata["home"] == "/home/vmail/some42@c3.testrun.org"
+    assert userdata["uid"] == userdata["gid"] == "vmail"
+    assert userdata["password"].startswith("{SHA512-CRYPT}")
diff --git a/tests/conftest.py b/tests/conftest.py
index b97536d7..8d8f0227 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -195,8 +195,8 @@ def gencreds(maildomain):
             num = next(count)
             alphanumeric = "abcdefghijklmnopqrstuvwxyz1234567890"
             user = "".join(random.choices(alphanumeric, k=10))
-            user = f"ac{num}_{user}"
-            password = "".join(random.choices(alphanumeric, k=10))
+            user = f"ac{num}_{user}"[:9]
+            password = "".join(random.choices(alphanumeric, k=12))
             yield f"{user}@{domain}", f"{password}"
 
     return lambda domain=None: next(gen(domain))