diff --git a/chatmaild/MANIFEST.in b/chatmaild/MANIFEST.in
index a11a04f9..625d48a3 100644
--- a/chatmaild/MANIFEST.in
+++ b/chatmaild/MANIFEST.in
@@ -1,3 +1,4 @@
 include src/chatmaild/*.f 
 include src/chatmaild/ini/*.ini.f
 include src/chatmaild/ini/*.ini
+include src/chatmaild/tests/mail-data/*
diff --git a/chatmaild/pyproject.toml b/chatmaild/pyproject.toml
index f0481a46..e87fc15b 100644
--- a/chatmaild/pyproject.toml
+++ b/chatmaild/pyproject.toml
@@ -20,6 +20,9 @@ where = ['src']
 doveauth = "chatmaild.doveauth:main"
 filtermail = "chatmaild.filtermail:main"
 
+[project.entry-points.pytest11]
+"chatmaild.testplugin" = "chatmaild.tests.plugin"
+
 [tool.pytest.ini_options]
 addopts = "-v -ra --strict-markers"
 log_format = "%(asctime)s %(levelname)s %(message)s"
@@ -45,5 +48,5 @@ commands =
 [testenv]
 deps = pytest 
        pdbpp 
-commands = pytest -v -rsXx {posargs: ../tests/chatmaild}
+commands = pytest -v -rsXx {posargs}
 """
diff --git a/tests/mail-data/encrypted.eml b/chatmaild/src/chatmaild/tests/mail-data/encrypted.eml
similarity index 100%
rename from tests/mail-data/encrypted.eml
rename to chatmaild/src/chatmaild/tests/mail-data/encrypted.eml
diff --git a/tests/mail-data/fake-encrypted.eml b/chatmaild/src/chatmaild/tests/mail-data/fake-encrypted.eml
similarity index 100%
rename from tests/mail-data/fake-encrypted.eml
rename to chatmaild/src/chatmaild/tests/mail-data/fake-encrypted.eml
diff --git a/tests/mail-data/mdn.eml b/chatmaild/src/chatmaild/tests/mail-data/mdn.eml
similarity index 100%
rename from tests/mail-data/mdn.eml
rename to chatmaild/src/chatmaild/tests/mail-data/mdn.eml
diff --git a/tests/mail-data/plain.eml b/chatmaild/src/chatmaild/tests/mail-data/plain.eml
similarity index 100%
rename from tests/mail-data/plain.eml
rename to chatmaild/src/chatmaild/tests/mail-data/plain.eml
diff --git a/chatmaild/src/chatmaild/tests/plugin.py b/chatmaild/src/chatmaild/tests/plugin.py
new file mode 100644
index 00000000..4a7e708a
--- /dev/null
+++ b/chatmaild/src/chatmaild/tests/plugin.py
@@ -0,0 +1,68 @@
+import random
+import importlib.resources
+import itertools
+from email.parser import BytesParser
+from email import policy
+import pytest
+
+from chatmaild.database import Database
+from chatmaild.config import read_config, write_initial_config
+
+
+@pytest.fixture
+def make_config(tmp_path):
+    inipath = tmp_path.joinpath("chatmail.ini")
+
+    def make_conf(mailname):
+        write_initial_config(inipath, mailname=mailname)
+        return read_config(inipath)
+
+    return make_conf
+
+
+@pytest.fixture
+def example_config(make_config):
+    return make_config("chat.example.org")
+
+
+@pytest.fixture
+def maildomain(example_config):
+    return example_config.mailname
+
+
+@pytest.fixture
+def gencreds(maildomain):
+    count = itertools.count()
+    next(count)
+
+    def gen(domain=None):
+        domain = domain if domain else maildomain
+        while 1:
+            num = next(count)
+            alphanumeric = "abcdefghijklmnopqrstuvwxyz1234567890"
+            user = "".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))
+
+
+@pytest.fixture()
+def db(tmpdir):
+    db_path = tmpdir / "passdb.sqlite"
+    print("database path:", db_path)
+    return Database(db_path)
+
+
+@pytest.fixture
+def maildata(request):
+    datadir = importlib.resources.files(__package__).joinpath("mail-data")
+    assert datadir.exists(), datadir
+
+    def maildata(name, from_addr, to_addr):
+        data = datadir.joinpath(name).read_text()
+        text = data.format(from_addr=from_addr, to_addr=to_addr)
+        return BytesParser(policy=policy.default).parsebytes(text.encode())
+
+    return maildata
diff --git a/tests/chatmaild/test_config.py b/chatmaild/src/chatmaild/tests/test_config.py
similarity index 100%
rename from tests/chatmaild/test_config.py
rename to chatmaild/src/chatmaild/tests/test_config.py
diff --git a/tests/chatmaild/test_doveauth.py b/chatmaild/src/chatmaild/tests/test_doveauth.py
similarity index 96%
rename from tests/chatmaild/test_doveauth.py
rename to chatmaild/src/chatmaild/tests/test_doveauth.py
index 07446861..23c0a1ab 100644
--- a/tests/chatmaild/test_doveauth.py
+++ b/chatmaild/src/chatmaild/tests/test_doveauth.py
@@ -59,8 +59,8 @@ def test_handle_dovecot_request(db):
     assert userdata["password"].startswith("{SHA512-CRYPT}")
 
 
-def test_100_concurrent_lookups_different_accounts(db, gencreds):
-    num_threads = 100
+def test_50_concurrent_lookups_different_accounts(db, gencreds):
+    num_threads = 50
     req_per_thread = 5
     results = queue.Queue()
 
diff --git a/tests/chatmaild/test_filtermail.py b/chatmaild/src/chatmaild/tests/test_filtermail.py
similarity index 83%
rename from tests/chatmaild/test_filtermail.py
rename to chatmaild/src/chatmaild/tests/test_filtermail.py
index 91f98a95..4db47d8d 100644
--- a/tests/chatmaild/test_filtermail.py
+++ b/chatmaild/src/chatmaild/tests/test_filtermail.py
@@ -26,27 +26,36 @@ def test_reject_forged_from(maildata, gencreds, handler):
         rcpt_tos = [gencreds()[0]]
 
     # test that the filter lets good mail through
-    env.content = maildata("plain.eml", from_addr=env.mail_from).as_bytes()
+    to_addr = gencreds()[0]
+    env.content = maildata(
+        "plain.eml", from_addr=env.mail_from, to_addr=to_addr
+    ).as_bytes()
 
     assert not handler.check_DATA(envelope=env)
 
     # test that the filter rejects forged mail
-    env.content = maildata("plain.eml", from_addr="forged@c3.testrun.org").as_bytes()
+    env.content = maildata(
+        "plain.eml", from_addr="forged@c3.testrun.org", to_addr=to_addr
+    ).as_bytes()
     error = handler.check_DATA(envelope=env)
     assert "500" in error
 
 
 def test_filtermail_no_encryption_detection(maildata):
-    msg = maildata("plain.eml")
+    msg = maildata(
+        "plain.eml", from_addr="some@example.org", to_addr="other@example.org"
+    )
     assert not check_encrypted(msg)
 
     # https://xkcd.com/1181/
-    msg = maildata("fake-encrypted.eml")
+    msg = maildata(
+        "fake-encrypted.eml", from_addr="some@example.org", to_addr="other@example.org"
+    )
     assert not check_encrypted(msg)
 
 
 def test_filtermail_encryption_detection(maildata):
-    msg = maildata("encrypted.eml")
+    msg = maildata("encrypted.eml", from_addr="1@example.org", to_addr="2@example.org")
     assert check_encrypted(msg)
 
     # if the subject is not "..." it is not considered ac-encrypted
diff --git a/tests/chatmaild/test_newmail.py b/chatmaild/src/chatmaild/tests/test_newmail.py
similarity index 100%
rename from tests/chatmaild/test_newmail.py
rename to chatmaild/src/chatmaild/tests/test_newmail.py
diff --git a/deploy-chatmail/pyproject.toml b/deploy-chatmail/pyproject.toml
index 39eed1d8..f480bec1 100644
--- a/deploy-chatmail/pyproject.toml
+++ b/deploy-chatmail/pyproject.toml
@@ -20,6 +20,9 @@ dependencies = [
 [project.scripts]
 cmdeploy = "deploy_chatmail.cmdeploy:main"
 
+[project.entry-points.pytest11]
+"chatmaild.testplugin" = "chatmaild.tests.plugin"
+
 [tool.pytest.ini_options]
 addopts = "-v -ra --strict-markers"
 
diff --git a/tests/conftest.py b/tests/conftest.py
index 4bef976d..d3a4e970 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -352,22 +352,6 @@ def lp(request):
     return LP()
 
 
-@pytest.fixture
-def maildata(request, gencreds):
-    datadir = conftestdir.joinpath("mail-data")
-
-    def maildata(name, from_addr=None, to_addr=None):
-        if from_addr is None:
-            from_addr = gencreds()[0]
-        if to_addr is None:
-            to_addr = gencreds()[0]
-        data = datadir.joinpath(name).read_text()
-        text = data.format(from_addr=from_addr, to_addr=to_addr)
-        return BytesParser(policy=policy.default).parsebytes(text.encode())
-
-    return maildata
-
-
 @pytest.fixture
 def cmsetup(maildomain, gencreds):
     return CMSetup(maildomain, gencreds)
@@ -414,16 +398,3 @@ class CMUser:
             imap.login(self.addr, self.password)
             self._imap = imap
         return self._imap
-
-
-@pytest.fixture
-def make_config(tmp_path):
-    from chatmaild.config import read_config, write_initial_config
-
-    inipath = tmp_path.joinpath("chatmail.ini")
-
-    def make_conf(mailname):
-        write_initial_config(inipath, mailname=mailname)
-        return read_config(inipath)
-
-    return make_conf
diff --git a/tests/online/test_1_basic.py b/tests/online/test_1_basic.py
index 31e877ad..a6705da5 100644
--- a/tests/online/test_1_basic.py
+++ b/tests/online/test_1_basic.py
@@ -20,7 +20,7 @@ def test_use_two_chatmailservers(cmfactory, maildomain2):
 
 
 @pytest.mark.parametrize("forgeaddr", ["internal", "someone@example.org"])
-def test_reject_forged_from(cmsetup, maildata, lp, forgeaddr):
+def test_reject_forged_from(cmsetup, maildata, gencreds, lp, forgeaddr):
     user1, user3 = cmsetup.gen_users(2)
 
     lp.sec("send encrypted message with forged from")
diff --git a/tests/test_cmdeploy.py b/tests/test_cmdeploy.py
index cad55bdd..c38fb930 100644
--- a/tests/test_cmdeploy.py
+++ b/tests/test_cmdeploy.py
@@ -24,7 +24,7 @@ class TestCmdline:
     def test_init(self, tmp_path):
         main(["init", "chat.example.org"])
         inipath = tmp_path.joinpath("chatmail.ini")
-        config = read_config(inipath.strpath)
+        config = read_config(inipath)
         assert config.mailname == "chat.example.org"
 
     def test_init_not_overwrite(self):