diff --git a/.flake8 b/.flake8
new file mode 100644
index 0000000..6deafc2
--- /dev/null
+++ b/.flake8
@@ -0,0 +1,2 @@
+[flake8]
+max-line-length = 120
diff --git a/anymail/__init__.py b/anymail/__init__.py
index 1107fd2..29089a0 100644
--- a/anymail/__init__.py
+++ b/anymail/__init__.py
@@ -1 +1,2 @@
-from ._version import __version__, VERSION
+# Expose package version at root of package
+from ._version import __version__, VERSION  # NOQA: F401
diff --git a/anymail/backends/base.py b/anymail/backends/base.py
index f6c1015..86319b9 100644
--- a/anymail/backends/base.py
+++ b/anymail/backends/base.py
@@ -282,7 +282,7 @@ class BasePayload(object):
 
     def validate_not_bare_string(self, attr, value):
         """EmailMessage to, cc, bcc, and reply_to are specced to be lists of strings.
-        
+
         This catches the common error where a single string is used instead.
         (See also checks in EmailMessage.__init__.)
         """
diff --git a/anymail/backends/mandrill.py b/anymail/backends/mandrill.py
index 14449f4..d45bc7d 100644
--- a/anymail/backends/mandrill.py
+++ b/anymail/backends/mandrill.py
@@ -214,7 +214,7 @@ class MandrillPayload(RequestsPayload):
                         {'rcpt': rcpt, 'values': recipient_metadata[rcpt]}
                         for rcpt in sorted(recipient_metadata.keys())]
             # Merge esp_extra with payload data: shallow merge within ['message'] and top-level keys
-            self.data.update({k:v for k,v in esp_extra.items() if k != 'message'})
+            self.data.update({k: v for k, v in esp_extra.items() if k != 'message'})
             try:
                 self.data['message'].update(esp_extra['message'])
             except KeyError:
@@ -311,4 +311,5 @@ class MandrillPayload(RequestsPayload):
         setter.__name__ = setter_name
         return setter
 
+
 MandrillPayload.define_message_attr_setters()
diff --git a/anymail/backends/sendgrid.py b/anymail/backends/sendgrid.py
index 3d2c5ea..7e4b718 100644
--- a/anymail/backends/sendgrid.py
+++ b/anymail/backends/sendgrid.py
@@ -344,4 +344,3 @@ class SendGridPayload(RequestsPayload):
                 "or use 'anymail.backends.sendgrid_v2.EmailBackend' for the old API."
             )
         update_deep(self.data, extra)
-
diff --git a/anymail/webhooks/sendgrid.py b/anymail/webhooks/sendgrid.py
index 24d5ad9..9f52c97 100644
--- a/anymail/webhooks/sendgrid.py
+++ b/anymail/webhooks/sendgrid.py
@@ -120,4 +120,3 @@ class SendGridTrackingWebhookView(SendGridBaseWebhookView):
         'url_offset',  # click tracking
         'useragent',  # click/open tracking
     }
-
diff --git a/docs/conf.py b/docs/conf.py
index 1b36af1..8da9da6 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -11,7 +11,8 @@
 # All configuration values have a default; values that are commented out
 # serve to show the default.
 
-import sys, os
+import os
+import sys
 on_rtd = os.environ.get('READTHEDOCS', None) == 'True'
 
 # If extensions (or modules to document with autodoc) are in another directory,
@@ -43,7 +44,7 @@ templates_path = ['_templates']
 source_suffix = '.rst'
 
 # The encoding of source files.
-#source_encoding = 'utf-8-sig'
+# source_encoding = 'utf-8-sig'
 
 # The master toctree document.
 master_doc = 'index'
@@ -64,13 +65,13 @@ release = __version__
 
 # The language for content autogenerated by Sphinx. Refer to documentation
 # for a list of supported languages.
-#language = None
+# language = None
 
 # There are two options for replacing |today|: either, you set today to some
 # non-false value, then it is used:
-#today = ''
+# today = ''
 # Else, today_fmt is used as the format for a strftime call.
-#today_fmt = '%B %d, %Y'
+# today_fmt = '%B %d, %Y'
 
 # List of patterns, relative to source directory, that match files and
 # directories to ignore when looking for source files.
@@ -80,21 +81,21 @@ exclude_patterns = ['_build']
 default_role = "py:obj"
 
 # If true, '()' will be appended to :func: etc. cross-reference text.
-#add_function_parentheses = True
+# add_function_parentheses = True
 
 # If true, the current module name will be prepended to all description
 # unit titles (such as .. function::).
-#add_module_names = True
+# add_module_names = True
 
 # If true, sectionauthor and moduleauthor directives will be shown in the
 # output. They are ignored by default.
-#show_authors = False
+# show_authors = False
 
 # The name of the Pygments (syntax highlighting) style to use.
 pygments_style = 'sphinx'
 
 # A list of ignored prefixes for module index sorting.
-#modindex_common_prefix = []
+# modindex_common_prefix = []
 
 
 # -- Options for HTML output ---------------------------------------------------
@@ -110,26 +111,26 @@ if not on_rtd:  # only import and set the theme if we're building docs locally
 # Theme options are theme-specific and customize the look and feel of a theme
 # further.  For a list of options available for each theme, see the
 # documentation.
-#html_theme_options = {}
+# html_theme_options = {}
 
 # Add any paths that contain custom themes here, relative to this directory.
-#html_theme_path = []
+# html_theme_path = []
 
 # The name for this set of Sphinx documents.  If None, it defaults to
 # "<project> v<release> documentation".
-#html_title = None
+# html_title = None
 
 # A shorter title for the navigation bar.  Default is the same as html_title.
-#html_short_title = None
+# html_short_title = None
 
 # The name of an image file (relative to this directory) to place at the top
 # of the sidebar.
-#html_logo = None
+# html_logo = None
 
 # The name of an image file (within the static path) to use as favicon of the
 # docs.  This file should be a Windows icon file (.ico) being 16x16 or 32x32
 # pixels large.
-#html_favicon = None
+# html_favicon = None
 
 # Add any paths that contain custom static files (such as style sheets) here,
 # relative to this directory. They are copied after the builtin static files,
@@ -138,44 +139,44 @@ html_static_path = ['_static']
 
 # If not '', a 'Last updated on:' timestamp is inserted at every page bottom,
 # using the given strftime format.
-#html_last_updated_fmt = '%b %d, %Y'
+# html_last_updated_fmt = '%b %d, %Y'
 
 # If true, SmartyPants will be used to convert quotes and dashes to
 # typographically correct entities.
-#html_use_smartypants = True
+# html_use_smartypants = True
 
 # Custom sidebar templates, maps document names to template names.
-#html_sidebars = {}
+# html_sidebars = {}
 
 # Additional templates that should be rendered to pages, maps page names to
 # template names.
-#html_additional_pages = {}
+# html_additional_pages = {}
 
 # If false, no module index is generated.
-#html_domain_indices = True
+# html_domain_indices = True
 
 # If false, no index is generated.
-#html_use_index = True
+# html_use_index = True
 
 # If true, the index is split into individual pages for each letter.
-#html_split_index = False
+# html_split_index = False
 
 # If true, links to the reST sources are added to the pages.
-#html_show_sourcelink = True
+# html_show_sourcelink = True
 
 # If true, "Created using Sphinx" is shown in the HTML footer. Default is True.
-#html_show_sphinx = True
+# html_show_sphinx = True
 
 # If true, "(C) Copyright ..." is shown in the HTML footer. Default is True.
-#html_show_copyright = True
+# html_show_copyright = True
 
 # If true, an OpenSearch description file will be output, and all pages will
 # contain a <link> tag referring to it.  The value of this option must be the
 # base URL from which the finished HTML is served.
-#html_use_opensearch = ''
+# html_use_opensearch = ''
 
 # This is the file name suffix for HTML files (e.g. ".xhtml").
-#html_file_suffix = None
+# html_file_suffix = None
 
 # Output file base name for HTML help builder.
 htmlhelp_basename = 'Anymaildoc'
@@ -184,14 +185,14 @@ htmlhelp_basename = 'Anymaildoc'
 # -- Options for LaTeX output --------------------------------------------------
 
 latex_elements = {
-# The paper size ('letterpaper' or 'a4paper').
-#'papersize': 'letterpaper',
+    # The paper size ('letterpaper' or 'a4paper').
+    # 'papersize': 'letterpaper',
 
-# The font size ('10pt', '11pt' or '12pt').
-#'pointsize': '10pt',
+    # The font size ('10pt', '11pt' or '12pt').
+    # 'pointsize': '10pt',
 
-# Additional stuff for the LaTeX preamble.
-#'preamble': '',
+    # Additional stuff for the LaTeX preamble.
+    # 'preamble': '',
 }
 
 # Grouping the document tree into LaTeX files. List of tuples
@@ -203,23 +204,23 @@ latex_documents = [
 
 # The name of an image file (relative to this directory) to place at the top of
 # the title page.
-#latex_logo = None
+# latex_logo = None
 
 # For "manual" documents, if this is true, then toplevel headings are parts,
 # not chapters.
-#latex_use_parts = False
+# latex_use_parts = False
 
 # If true, show page references after internal links.
-#latex_show_pagerefs = False
+# latex_show_pagerefs = False
 
 # If true, show URL addresses after external links.
-#latex_show_urls = False
+# latex_show_urls = False
 
 # Documents to append as an appendix to all manuals.
-#latex_appendices = []
+# latex_appendices = []
 
 # If false, no module index is generated.
-#latex_domain_indices = True
+# latex_domain_indices = True
 
 
 # -- Options for manual page output --------------------------------------------
@@ -232,7 +233,7 @@ man_pages = [
 ]
 
 # If true, show URL addresses after external links.
-#man_show_urls = False
+# man_show_urls = False
 
 
 # -- Options for Texinfo output ------------------------------------------------
@@ -247,13 +248,13 @@ texinfo_documents = [
 ]
 
 # Documents to append as an appendix to all manuals.
-#texinfo_appendices = []
+# texinfo_appendices = []
 
 # If false, no module index is generated.
-#texinfo_domain_indices = True
+# texinfo_domain_indices = True
 
 # How to display URL addresses: 'footnote', 'no', or 'inline'.
-#texinfo_show_urls = 'footnote'
+# texinfo_show_urls = 'footnote'
 
 
 # -- Options for Intersphinx ------------------------------------------------
diff --git a/setup.py b/setup.py
index 9fe0fcc..b5462a4 100644
--- a/setup.py
+++ b/setup.py
@@ -20,9 +20,11 @@ def long_description_from_readme(rst):
                  release, rst)  # (?<=...) is "positive lookbehind": must be there, but won't get replaced
     return rst
 
+
 with open('README.rst') as f:
     long_description = long_description_from_readme(f.read())
 
+
 setup(
     name="django-anymail",
     version=__version__,
diff --git a/tests/test_general_backend.py b/tests/test_general_backend.py
index 5901392..6906581 100644
--- a/tests/test_general_backend.py
+++ b/tests/test_general_backend.py
@@ -315,4 +315,3 @@ class CatchCommonErrorsTests(TestBackendTestCase):
         self.message.reply_to = ugettext_lazy("single-reply-to@example.com")
         with self.assertRaisesMessage(TypeError, '"reply_to" attribute must be a list or other iterable'):
             self.message.send()
-
diff --git a/tests/test_mailgun_backend.py b/tests/test_mailgun_backend.py
index bb1f3e5..de44e26 100644
--- a/tests/test_mailgun_backend.py
+++ b/tests/test_mailgun_backend.py
@@ -526,4 +526,3 @@ class MailgunBackendDeprecationTests(MailgunBackendMockAPITestCase):
         with self.assertWarnsRegex(DeprecationWarning,
                                    r'anymail\.backends\.mailgun\.EmailBackend'):
             self.message.send()
-
diff --git a/tests/test_mandrill_backend.py b/tests/test_mandrill_backend.py
index 8a486fb..f322145 100644
--- a/tests/test_mandrill_backend.py
+++ b/tests/test_mandrill_backend.py
@@ -416,7 +416,7 @@ class MandrillBackendAnymailFeatureTests(MandrillBackendMockAPITestCase):
             # Anymail expands simple python dicts into the more-verbose
             # rcpt/values lists the Mandrill API uses
             "customer@example.com": {'cust_id': "67890", 'order_id': "54321"},
-            "guest@example.com": {'cust_id': "94107", 'order_id': "43215"} ,
+            "guest@example.com": {'cust_id': "94107", 'order_id': "43215"},
         }}}
         self.message.send()
         data = self.get_api_call_json()
diff --git a/tests/test_postmark_webhooks.py b/tests/test_postmark_webhooks.py
index 85c657e..99d6db5 100644
--- a/tests/test_postmark_webhooks.py
+++ b/tests/test_postmark_webhooks.py
@@ -106,4 +106,3 @@ class PostmarkDeliveryTestCase(WebhookTestCase):
         self.assertEqual(event.message_id, "f4830d10-9c35-4f0c-bca3-3d9b459821f8")
         self.assertEqual(event.recipient, "recipient@example.com")
         self.assertEqual(event.user_agent, "Mozilla/5.0 (Windows NT 5.1; rv:11.0) Gecko Firefox/11.0")
-
diff --git a/tests/test_sendgrid_backend.py b/tests/test_sendgrid_backend.py
index a6a47fc..0c42ef2 100644
--- a/tests/test_sendgrid_backend.py
+++ b/tests/test_sendgrid_backend.py
@@ -599,9 +599,9 @@ class SendGridBackendAnymailFeatureTests(SendGridBackendMockAPITestCase):
                        ['"Recipient, Ltd." <to@example.com>'])
         data = self.get_api_call_json()
         self.assertEqual(data["personalizations"][0]["to"][0],
-            {"email": "to@example.com", "name": "Recipient, Ltd."})  # no extra quotes on name
+                         {"email": "to@example.com", "name": "Recipient, Ltd."})  # no extra quotes on name
         self.assertEqual(data["from"],
-            {"email": "from@example.com", "name": "Sender, Inc."})
+                         {"email": "from@example.com", "name": "Sender, Inc."})
 
 
 class SendGridBackendRecipientsRefusedTests(SendGridBackendMockAPITestCase):
diff --git a/tests/test_utils.py b/tests/test_utils.py
index c572436..f6315ec 100644
--- a/tests/test_utils.py
+++ b/tests/test_utils.py
@@ -112,7 +112,7 @@ class LazyCoercionTests(SimpleTestCase):
 
     def test_force_dict(self):
         result = force_non_lazy_dict({'a': 1, 'b': ugettext_lazy(u"b"),
-                                 'c': {'c1': ugettext_lazy(u"c1")}})
+                                      'c': {'c1': ugettext_lazy(u"c1")}})
         self.assertEqual(result, {'a': 1, 'b': u"b", 'c': {'c1': u"c1"}})
         self.assertIsInstance(result['b'], six.text_type)
         self.assertIsInstance(result['c']['c1'], six.text_type)
diff --git a/tests/utils.py b/tests/utils.py
index 89daec1..ad92a02 100644
--- a/tests/utils.py
+++ b/tests/utils.py
@@ -167,8 +167,7 @@ class _AssertWarnsContext(object):
                 continue
             if first_matching is None:
                 first_matching = w
-            if (self.expected_regex is not None and
-                not self.expected_regex.search(str(w))):
+            if self.expected_regex is not None and not self.expected_regex.search(str(w)):
                 continue
             # store warning for later retrieval
             self.warning = w