diff --git a/Lib/test/test_imaplib.py b/Lib/test/test_imaplib.py
--- a/Lib/test/test_imaplib.py
+++ b/Lib/test/test_imaplib.py
@@ -172,6 +172,76 @@
         self._send_tagged(tag, 'OK', 'LOGIN completed')
 
 
+class NewIMAPTests(unittest.TestCase):
+
+    def _setup(self, imap_server):
+        """
+        Setups imap_server (which should inherit SimpleIMAPHandler) for tests.
+        Returns (client, server).
+        """
+        class TestTCPServer(socketserver.TCPServer):
+            def handle_error(self, request, client_address):
+                """
+                End request and raise the error if one occurs.
+                """
+                self.close_request(request)
+                self.server_close()
+                raise
+
+        server = TestTCPServer((support.HOST, 0), imap_server)
+        thread = threading.Thread(
+            name=server.__class__.__name__,
+            target=server.serve_forever,
+            # Short poll interval to make the test finish quickly.
+            # Time between requests is short enough that we won't wake
+            # up spuriously too many times.
+            kwargs={'poll_interval': 0.01})
+        thread.daemon = True  # In case this function raises.
+        thread.start()
+
+        client = imaplib.IMAP4(*server.server_address)
+
+        # cleaning up (LIFO order)
+        self.addCleanup(thread.join)
+        self.addCleanup(server.server_close)
+        self.addCleanup(server.shutdown)
+        # if logout was called already we'd raise an exception trying to
+        # shutdown the client once again
+        self.addCleanup(lambda c: c.shutdown() if c.state != 'LOGOUT'
+                                                    else None, client)
+
+        return client, server
+
+
+    def test_login(self):
+        client, _ = self._setup(SimpleIMAPHandler)
+        typ, data = client.login('user', 'pass')
+        self.assertEqual(typ, 'OK')
+        self.assertEqual(data[0], b'LOGIN completed')
+        self.assertEqual(client.state, 'AUTH')
+
+    def test_logout(self):
+        client, _ = self._setup(SimpleIMAPHandler)
+        typ, data = client.login('user', 'pass')
+        self.assertEqual(typ, 'OK')
+        self.assertEqual(data[0], b'LOGIN completed')
+        typ, data = client.logout()
+        self.assertEqual(typ, 'BYE')
+        self.assertEqual(data[0], b'IMAP4ref1 Server logging out')
+        self.assertEqual(client.state, 'LOGOUT')
+
+    def test_lsub(self):
+        class LsubCmd(SimpleIMAPHandler):
+            def cmd_LSUB(self, tag, args):
+                self._send_textline('* LSUB () "." directoryA')
+                return self._send_tagged(tag, 'OK', 'LSUB completed')
+        client, _ = self._setup(LsubCmd)
+        client.login('user', 'pass')
+        typ, data = client.lsub()
+        self.assertEqual(typ, 'OK')
+        self.assertEqual(data[0], b'() "." directoryA')
+
+
 class ThreadedNetworkedTests(unittest.TestCase):
     server_class = socketserver.TCPServer
     imap_class = imaplib.IMAP4
@@ -615,5 +685,9 @@
                 keyfile=CERTFILE, ssl_context=self.create_ssl_context())
 
 
-if __name__ == "__main__":
-    unittest.main()
+@support.reap_threads
+def test_main(verbose=None):
+    support.run_unittest(NewIMAPTests)
+
+if __name__ == '__main__':
+    test_main()