diff --git a/certbot-postfix/certbot_postfix/installer.py b/certbot-postfix/certbot_postfix/installer.py
index be80b88af..11d948cb6 100644
--- a/certbot-postfix/certbot_postfix/installer.py
+++ b/certbot-postfix/certbot_postfix/installer.py
@@ -42,6 +42,7 @@ class Installer(plugins_common.Installer):
     def add_parser_arguments(cls, add):
         add("ctl", default=constants.CLI_DEFAULTS["ctl"],
             help="Path to the 'postfix' control program.")
+        # This directory points to Postfix's configuration directory.
         add("config-dir", default=constants.CLI_DEFAULTS["config_dir"],
             help="Path to the directory containing the "
             "Postfix main.cf file to modify instead of using the "
@@ -52,6 +53,7 @@ class Installer(plugins_common.Installer):
             help="Name of the policy file that we should write to in config-dir.")
 
     def _verify_setup(self):
+        # TODO (sydneyli): do this
         pass
 
     def __init__(self, *args, **kwargs):
@@ -71,8 +73,12 @@ class Installer(plugins_common.Installer):
         self.postfix = None
         self.policy_file = None
         self._enhance_func = {"starttls-policy": self._enable_policy_list}
+        # Since we only need to enable policy once for all domains,
+        # keep track of whether this enhancement was already called.
+        self._starttls_policy_enabled = False
 
     def _ensure_ca_certificates_exist(self):
+        # TODO (sydneyli): This might block starttls-everywhere
         # TODO (sydneyli): Ensure `ca-certificates` is installed correctly, or that
         # /etc/ssl/certs/ even has certificates in it, probably via a sanity check using
         # `openssl` command?
@@ -124,7 +130,8 @@ class Installer(plugins_common.Installer):
 
         """
         if self._get_version() < constants.MINIMUM_VERSION:
-            raise errors.NotSupportedError('Postfix version is too old')
+            version_string = '.'.join([str(n) for n in constants.MINIMUM_VERSION])
+            raise errors.NotSupportedError('Postfix version must be at least %s', version_string)
 
     def _lock_config_dir(self):
         """Stop two Postfix plugins from modifying the config at once.
@@ -216,11 +223,14 @@ class Installer(plugins_common.Installer):
                           check_override=util.report_master_overrides)
 
     def _enable_policy_list(self, domain, options):
+        if self._starttls_policy_enabled:
+            return
+        self._starttls_policy_enabled = True
         # pylint: disable=unused-argument
         try:
             from starttls_policy import policy
         except ImportError:
-            raise ImportError('STARTTLS Everywhere policy Python module not installed!')
+            raise errors.PluginError('STARTTLS Everywhere policy Python module not installed!')
         if options is None:
             policy = policy.Config()
         else:
@@ -232,10 +242,6 @@ class Installer(plugins_common.Installer):
 
     def enhance(self, domain, enhancement, options=None):
         """Raises an exception for request for unsupported enhancement.
-
-        :raises .PluginError: this is always raised as no enhancements
-            are currently supported
-
         """
         try:
             func = self._enhance_func[enhancement]
@@ -254,7 +260,7 @@ class Installer(plugins_common.Installer):
         :rtype: list
 
         """
-        return ['starttls-policy'] # TODO(sydneyli): Call this starttls-policy?
+        return ['starttls-policy']
 
     def save(self, title=None, temporary=False):
         """Creates backups and writes changes to configuration files.
diff --git a/certbot-postfix/certbot_postfix/postconf.py b/certbot-postfix/certbot_postfix/postconf.py
index d2af43174..6c34adbcb 100644
--- a/certbot-postfix/certbot_postfix/postconf.py
+++ b/certbot-postfix/certbot_postfix/postconf.py
@@ -5,6 +5,8 @@ from certbot import errors
 from certbot_postfix import util
 
 
+# TODO (sydneyli): tox-ify and make sure this runs in Python 3.
+
 class ConfigMain(util.PostfixUtilBase):
     """A parser for Postfix's main.cf file."""
 
@@ -36,28 +38,28 @@ class ConfigMain(util.PostfixUtilBase):
             self._master_db[param_name].append((service, value))
 
     def get_default(self, name):
-        """Retrieves default value of parameter |name| from postfix parameters.
+        """Retrieves default value of parameter `name` from postfix parameters.
             :param str name: The name of the parameter to fetch.
-            :rtype str: The default value of parameter |name|.
+            :rtype str: The default value of parameter `name`.
         """
         out = self._get_output(['-d', name])
         _, value = next(_parse_main_output(out), (None, None))
         return value
 
     def get(self, name):
-        """Retrieves working value of parameter |name| from postfix parameters.
+        """Retrieves working value of parameter `name` from postfix parameters.
             :param str name: The name of the parameter to fetch.
-            :rtype str: The value of parameter |name|.
+            :rtype str: The value of parameter `name`.
         """
         if name in self._updated:
             return self._updated[name]
         return self._db[name]
 
     def get_master_overrides(self, name):
-        """Retrieves list of overrides for parameter |name| in postfix's Master config
+        """Retrieves list of overrides for parameter `name` in postfix's Master config
         file.
-            :returns: List of tuples (service, value), meaning that parameter |name|
-                      is overridden as |value| for |service|.
+            :returns: List of tuples (service, value), meaning that parameter `name`
+                      is overridden as `value` for `service`.
             :rtype `list` of `tuple` of `str:
         """
         if name in self._master_db:
@@ -65,33 +67,26 @@ class ConfigMain(util.PostfixUtilBase):
         return None
 
     def set(self, name, value, check_override=None):
-        """Sets parameter |name| to |value|.
-        If |name| is overridden by a particular service in `master.cf`, calls
-        `check_override` on |name|, and the set of overrides.
+        """Sets parameter `name` to `value`.
+        If `name` is overridden by a particular service in `master.cf`, calls
+        `check_override` on `name`, and the set of overrides.
 
         Note that this function does not flush these parameter values to main.cf;
-        To do that, use |flush|.
+        To do that, use `flush`.
             :param str name: The name of the parameter to set.
             :param str value: The value of the parameter.
         """
         if name not in self._db:
-            return # TODO: error here
+            return
         # Check to see if this parameter is overridden by master.
+        # TODO: comment the below
         overrides = self.get_master_overrides(name)
         if check_override is not None and overrides is not None:
             check_override(name, overrides)
-        # We've updated this name before.
-        if name in self._updated:
-            if value == self._updated[name]:
-                return
-            if value == self._db[name]:
-                del self._updated[name]
-                return
-        # We haven't updated this name before.
-        else:
-            # If we're just setting the default value, ignore.
-            if value != self._db[name]:
-                self._updated[name] = value
+        if value != self._db[name]:
+            self._updated[name] = value
+        elif name in self._updated:
+            del self._updated[name]
 
     def flush(self):
         """Flushes all parameter changes made using "self.set" to "main.cf".
diff --git a/certbot-postfix/certbot_postfix/tests/installer_test.py b/certbot-postfix/certbot_postfix/tests/installer_test.py
index 07b80d60d..a6f55bf5a 100644
--- a/certbot-postfix/certbot_postfix/tests/installer_test.py
+++ b/certbot-postfix/certbot_postfix/tests/installer_test.py
@@ -11,7 +11,6 @@ from certbot import errors
 from certbot.tests import util as certbot_test_util
 
 class InstallerTest(certbot_test_util.ConfigTestCase):
-    # pylint: disable=too-many-public-methods
 
     def setUp(self):
         super(InstallerTest, self).setUp()
diff --git a/certbot-postfix/certbot_postfix/tests/postconf_test.py b/certbot-postfix/certbot_postfix/tests/postconf_test.py
index 1b0cc376b..b28a20b05 100644
--- a/certbot-postfix/certbot_postfix/tests/postconf_test.py
+++ b/certbot-postfix/certbot_postfix/tests/postconf_test.py
@@ -8,6 +8,9 @@ import string
 import tempfile
 import unittest
 
+# TODO (sydneyli): Mock out calls to postconf
+# TODO (sydneyli): inherit certbot.tests.util.TempDirTestCase
+
 def _rand_str(n):
     """Returns a random string with length n, for use as a temporary directory."""
     return ''.join([random.choice(string.lowercase) for _ in xrange(n)])
diff --git a/certbot-postfix/certbot_postfix/util.py b/certbot-postfix/certbot_postfix/util.py
index 0eb794ff1..ba4ac9468 100644
--- a/certbot-postfix/certbot_postfix/util.py
+++ b/certbot-postfix/certbot_postfix/util.py
@@ -29,14 +29,6 @@ class PostfixUtilBase(object):
         self._set_base_command(config_dir)
         self.config_dir = None
 
-    def update_dir(self, config_dir):
-        """Updates the directory of the configuration files for Postfix.
-
-        :param str config_dir: The path containing the Postfix configuration files.
-        """
-        self.config_dir = config_dir
-        self._set_base_command(config_dir)
-
     def _set_base_command(self, config_dir):
         self._base_command = [self.executable]
         if config_dir is not None:
diff --git a/certbot/client.py b/certbot/client.py
index a0d9257df..ee38fdc5e 100644
--- a/certbot/client.py
+++ b/certbot/client.py
@@ -481,7 +481,7 @@ class Client(object):
             if enhancement_name in supported:
                 if config_name == "redirect" and config_value is None:
                     config_value = enhancements.ask(enhancement_name)
-                if config_name == "starttls_policy" and len(config_value) > 0:
+                if config_name == "starttls_policy" and config_value is not None:
                     option = config_value
                 if config_value:
                     self.apply_enhancement(domains, enhancement_name, option)
diff --git a/certbot/constants.py b/certbot/constants.py
index 3a330aeca..e19a99747 100644
--- a/certbot/constants.py
+++ b/certbot/constants.py
@@ -60,7 +60,7 @@ CLI_DEFAULTS = dict(
     hsts=None,
     uir=None,
     staple=None,
-    starttls_policy="",
+    starttls_policy=None,
     strict_permissions=False,
     pref_challs=[],
     validate_hooks=True,