diff --git a/.github/workflows/run_tests.yml b/.github/workflows/run_tests.yml
new file mode 100644
index 0000000..c939306
--- /dev/null
+++ b/.github/workflows/run_tests.yml
@@ -0,0 +1,41 @@
+name: run_tests
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+    branches:
+      - main
+jobs:
+  lint:
+    name: lint
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-python@v2
+        with:
+          python-version: ${{ matrix.python }}
+      - name: "Installs dependencies"
+        run: |
+          pip install -U pip wheel
+          pip install -e .[test]
+      - name: "Run linter"
+        run: make lint
+  tests:
+    name: tests
+    strategy:
+      matrix:
+        python: ["3.7", "3.8", "3.9", "3.10", "3.11"]
+      fail-fast: false
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-python@v2
+        with:
+          python-version: ${{ matrix.python }}
+      - name: "Installs dependencies"
+        run: |
+          pip install -U pip wheel
+          pip install -e .[test]
+      - name: "Run tests"
+        run: make test
diff --git a/.github/workflows/upload-to-pypi.yml b/.github/workflows/upload-to-pypi.yml
new file mode 100644
index 0000000..600a764
--- /dev/null
+++ b/.github/workflows/upload-to-pypi.yml
@@ -0,0 +1,32 @@
+name: Upload to PyPI
+
+on:
+  # Triggers the workflow when a release is created
+  release:
+    types: [created]
+  # Allows you to run this workflow manually from the Actions tab
+  workflow_dispatch:
+
+jobs:
+  upload:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-python@v2
+        with:
+          python-version: 3.9
+
+      - name: "Installs dependencies"
+        run: |
+          python3 -m pip install --upgrade pip
+          python3 -m pip install setuptools wheel build twine
+
+      - name: "Builds and uploads to PyPI"
+        run: |
+          python3 -m build
+          python3 -m twine check dist/*
+          python3 -m twine upload dist/*
+
+        env:
+          TWINE_USERNAME: __token__
+          TWINE_PASSWORD: ${{ secrets.TWINE_TOKEN }}
diff --git a/.travis.yml b/.travis.yml
deleted file mode 100755
index cba73ed..0000000
--- a/.travis.yml
+++ /dev/null
@@ -1,11 +0,0 @@
-dist: bionic
-language: python
-python:
-  - "3.6"
-  - "3.7"
-  - "3.8"
-
-before_install: pip install -U pip coveralls
-install: pip install .[test]
-script: pytest -Wd --cov mailshake --cov tests .
-after_success: coveralls
diff --git a/CHANGELOG.md b/CHANGELOG.md
deleted file mode 100644
index 2ebae7c..0000000
--- a/CHANGELOG.md
+++ /dev/null
@@ -1,9 +0,0 @@
-## 2.2
-Several bugfixes, internal improvements, and code cleanup, almost entirely by @Changaco
-
-- Prune some remnants of Python 2 compatibility
-- Prevent SMTP test failures from causing deadlocks
-- Clean up and refactor message rendering
-- Add a `host_id` argument to `make_msgid`
-- Improve the uniqueness of generated message IDs
-- Add proper timeouts to SMTP tests
diff --git a/mailshake/mailers/amazon_ses.py b/mailshake/mailers/amazon_ses.py
index ece8f28..dd96ccc 100755
--- a/mailshake/mailers/amazon_ses.py
+++ b/mailshake/mailers/amazon_ses.py
@@ -20,8 +20,7 @@ def __init__(
         *args,
         **kwargs
     ):
-        """
-        """
+        """ """
         import boto3
 
         self.client = boto3.client(
@@ -35,8 +34,7 @@ def __init__(
         super(AmazonSESMailer, self).__init__(*args, **kwargs)
 
     def send_messages(self, *email_messages):
-        """
-        """
+        """ """
         logger = logging.getLogger("mailshake:AmazonSESMailer")
         if not email_messages:
             logger.debug("No email messages to send")
diff --git a/mailshake/mailers/filebased.py b/mailshake/mailers/filebased.py
index ccb8977..6f0f608 100755
--- a/mailshake/mailers/filebased.py
+++ b/mailshake/mailers/filebased.py
@@ -40,8 +40,7 @@ def __init__(self, path, multifile=True, *args, **kwargs):
         super(ToFileMailer, self).__init__(*args, **kwargs)
 
     def _get_filename(self):
-        """Return a unique file name.
-        """
+        """Return a unique file name."""
         if self._fname is None:
             now = datetime.datetime.now()
             timestamp = now.strftime("%Y%m%d-%H%M%S")
diff --git a/mailshake/mailers/memory.py b/mailshake/mailers/memory.py
index 8be93e8..289b0d6 100755
--- a/mailshake/mailers/memory.py
+++ b/mailshake/mailers/memory.py
@@ -17,7 +17,6 @@ def __init__(self, *args, **kwargs):
         super(ToMemoryMailer, self).__init__(*args, **kwargs)
 
     def send_messages(self, *email_messages):
-        """Redirect messages to the dummy outbox.
-        """
+        """Redirect messages to the dummy outbox."""
         self.outbox.extend(email_messages)
         return len(email_messages)
diff --git a/mailshake/mailers/smtp.py b/mailshake/mailers/smtp.py
index e8d0c17..7305aa8 100755
--- a/mailshake/mailers/smtp.py
+++ b/mailshake/mailers/smtp.py
@@ -87,8 +87,7 @@ def open(self, hostname=None):
         return True
 
     def close(self):
-        """Closes the connection to the email server.
-        """
+        """Closes the connection to the email server."""
         if self.connection is None:
             return
         try:
@@ -125,8 +124,7 @@ def send_messages(self, *email_messages):
         return num_sent
 
     def _send(self, message):
-        """A helper method that does the actual sending.
-        """
+        """A helper method that does the actual sending."""
         recipients = message.get_recipients()
         if not recipients:
             return False
diff --git a/mailshake/message.py b/mailshake/message.py
index 59197ce..99a7286 100755
--- a/mailshake/message.py
+++ b/mailshake/message.py
@@ -86,8 +86,7 @@ def __init__(
 
 class EmailMessage:
 
-    """A container for email information.
-    """
+    """A container for email information."""
 
     content_subtype = "plain"
     mixed_subtype = "mixed"
diff --git a/mailshake/utils.py b/mailshake/utils.py
index b5776f1..3d2c210 100755
--- a/mailshake/utils.py
+++ b/mailshake/utils.py
@@ -114,8 +114,7 @@ def make_msgid(idstring=None, host_id=DNS_NAME):
 
 
 def forbid_multi_line_headers(name, val):
-    """Forbids multi-line headers, to prevent header injection.
-    """
+    """Forbids multi-line headers, to prevent header injection."""
     if "\n" in val or "\r" in val:
         raise ValueError(
             "Header values can't contain newlines "
@@ -124,8 +123,7 @@ def forbid_multi_line_headers(name, val):
 
 
 def to_str(s, encoding="utf-8", errors="strict"):
-    """Force a string to be the native text_type
-    """
+    """Force a string to be the native text_type"""
     if isinstance(s, str):
         return s
     return str(s, encoding, errors)
diff --git a/setup.cfg b/setup.cfg
index 18d34de..5f8b7b8 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -1,6 +1,6 @@
 [metadata]
 name = mailshake
-version= 2.2
+version = 2.3
 url = https://github.com/jpsca/mailshake
 project_urls =
     Issue tracker = https://github.com/jpsca/mailshake/issues
@@ -32,8 +32,10 @@ test =
     flake8
     pytest
     pytest-cov
+    smtpdfix
 
 dev =
+    black
     flake8
     pytest
     pytest-cov
@@ -41,23 +43,37 @@ dev =
 
 [flake8]
 select =
-  B,  # bugbear
-  B9,  # bugbear opinionated
-  C,  # mccabe, comprehensions, commas
-  E,  # pycodestyle errors
-  F,  # pyflakes
-  G,  # logging format
-  I,  # imports
+  # bugbear
+  B,
+  # bugbear opinionated
+  B9,
+  # mccabe, comprehensions, commas
+  C,
+  # pycodestyle errors
+  E,
+  # pyflakes
+  F,
+  # logging format
+  G,
+  # imports
+  I,
   P,
-  Q,  # quotes
-  RST,  # rst docstring formatting
-  T0,  # print
-  T4,  # mypy
-  W,  # pycodestyle warnings
+  # quotes
+  Q,
+  # rst docstring formatting
+  RST,
+  # print
+  T0,
+  # mypy
+  T4,
+  # pycodestyle warnings
+  W,
 
 ignore =
-    W503,  # W503 line break before binary operator
-    E203,  # E203 whitespace before ':'
+    # W503 line break before binary operator
+    W503,
+    # E203 whitespace before ':'
+    E203,
 
 max-complexity = 10
 max-line-length = 88
diff --git a/tests/test_mailers.py b/tests/test_mailers.py
index 1e280dd..664db42 100755
--- a/tests/test_mailers.py
+++ b/tests/test_mailers.py
@@ -81,8 +81,7 @@ def test_to_console_mailer():
 
 
 def test_to_console_stream_kwarg():
-    """Test that the console backend can be pointed at an arbitrary stream.
-    """
+    """Test that the console backend can be pointed at an arbitrary stream."""
     s = StringIO()
     mailer = ToConsoleMailer(stream=s)
     mailer.send("Subject", "Content", "from@example.com", "to@example.com")
diff --git a/tests/test_message.py b/tests/test_message.py
index 33f4a7f..d60605f 100755
--- a/tests/test_message.py
+++ b/tests/test_message.py
@@ -216,8 +216,7 @@ def test_message_header_overrides():
 
 
 def test_from_header():
-    """Make sure we can manually set the From header.
-    """
+    """Make sure we can manually set the From header."""
     email = EmailMessage(
         "Subject",
         "Content",
@@ -436,8 +435,7 @@ def test_dont_mangle_from_in_body():
 
 
 def test_dont_base64_encode():
-    """Shouldn't use Base64 encoding at all.
-    """
+    """Shouldn't use Base64 encoding at all."""
     email = EmailMessage(
         "Subject",
         "UTF-8 encoded body",
@@ -505,15 +503,22 @@ def test_invalid_destination():
     assert message["To"] != dest
 
 
+rx_message_id = re.compile(
+    r"^<[0-9]{14}\.[0-9]+\.[0-9a-f]+\.[0-9]+@[a-z0-9\-]+(\.[a-z0-9\-]+)*>$",
+    re.IGNORECASE,
+)
+
+
 def test_message_id():
-    message_id_re = re.compile(
-        r"^<[0-9]{14}\.[0-9]+\.[0-9a-f]+\.[0-9]+@[a-z\-]+(\.[a-z\-]+)*>$",
-        re.IGNORECASE
-    )
     email1 = EmailMessage("Subject 1", "Content", "from@example.com", "to@example.com")
     msg1 = email1.render()
-    assert message_id_re.match(msg1["Message-ID"])
+    mid1 = msg1["Message-ID"]
+    print("Message-ID 1:", mid1)
+    assert rx_message_id.match(mid1)
+
     email2 = EmailMessage("Subject 2", "Content", "from@example.com", "to@example.com")
     msg2 = email2.render()
-    assert message_id_re.match(msg2["Message-ID"])
-    assert msg2["Message-ID"] != msg1["Message-ID"]
+    mid2 = msg2["Message-ID"]
+    print("Message-ID 2:", mid2)
+    assert rx_message_id.match(mid2)
+    assert mid2 != mid1
diff --git a/tests/test_smtp_mailer.py b/tests/test_smtp_mailer.py
index 26e77c6..ec393ff 100755
--- a/tests/test_smtp_mailer.py
+++ b/tests/test_smtp_mailer.py
@@ -1,10 +1,5 @@
-import asyncore
-from email import message_from_bytes
-import smtpd
-from smtplib import SMTPException
-import threading
-
 import pytest
+from smtplib import SMTP, SMTPException
 
 from ..mailshake import EmailMessage, SMTPMailer
 
@@ -18,69 +13,18 @@ def make_emails():
     ]
 
 
-smtp_server = None
-SMTP_HOST = "127.0.0.1"
-SMTP_PORT = 8080
-
-
-class FakeSMTPServer(smtpd.SMTPServer):
-    """A Fake smtp server"""
-
-    def __init__(self, host, port):
-        print("Running fake SMTP server")
-        localaddr = (host, port)
-        remoteaddr = None
-        smtpd.SMTPServer.__init__(self, localaddr, remoteaddr)
-        self.flush_sink()
-
-    def flush_sink(self):
-        self.sink = []
-
-    def process_message(self, peer, from_, to, bmessage, **kwargs):
-        self.sink.append(message_from_bytes(bmessage))
-
-    def start(self):
-        # timeout parameter is important, otherwise code will block 30 seconds after
-        # the SMTP channel has been closed
-        self.thread = threading.Thread(target=asyncore.loop, kwargs={"timeout": 0.1})
-        self.thread.daemon = True
-        self.thread.start()
-
-    def stop(self):
-        # close the SMTPserver to ensure no channels connect to asyncore
-        self.close()
-        # now it is save to wait for the thread to finish,
-        # i.e. for asyncore.loop() to exit
-        self.thread.join(timeout=0.5)
-
-
-def setup_module():
-    global smtp_server
-    smtp_server = FakeSMTPServer(SMTP_HOST, SMTP_PORT)
-    smtp_server.start()
-
-
-def teardown_module():
-    global smtp_server
-    if smtp_server is not None:
-        smtp_server.stop()
-
-
-def test_sending():
-    global smtp_server
-    smtp_server.flush_sink()
-
-    mailer = SMTPMailer(host=SMTP_HOST, port=SMTP_PORT, use_tls=False)
+def test_sending(smtpd):
+    mailer = SMTPMailer(host=smtpd.hostname, port=smtpd.port, use_tls=False)
     email1, email2, email3, email4 = make_emails()
 
-    assert mailer.send_messages(email1) == 1
-    assert mailer.send_messages(email2, email3) == 2
-    assert mailer.send_messages(email4) == 1
+    with SMTP(smtpd.hostname, smtpd.port):
+        assert mailer.send_messages(email1) == 1
+        assert mailer.send_messages(email2, email3) == 2
+        assert mailer.send_messages(email4) == 1
 
-    sink = smtp_server.sink
-    assert len(sink) == 4
+    assert len(smtpd.messages) == 4
 
-    message = sink[0]
+    message = smtpd.messages[0]
     print(message)
     assert message.get_content_type() == "text/plain"
     assert message.get("subject") == "Subject-1"
@@ -88,77 +32,101 @@ def test_sending():
     assert message.get("to") == "to@example.com"
 
 
-def test_sending_unicode():
-    global smtp_server
-    smtp_server.flush_sink()
-
-    mailer = SMTPMailer(host="127.0.0.1", port=SMTP_PORT, use_tls=False)
+def test_sending_unicode(smtpd):
+    mailer = SMTPMailer(host=smtpd.hostname, port=smtpd.port, use_tls=False)
     email = EmailMessage(
-        "Olé", "Contenido en español", "from@example.com", "toБ@example.com"
+        subject="Olé",
+        text="Contenido en español",
+        from_email="from@example.com",
+        to="toБ@example.com",
     )
-    assert mailer.send_messages(email)
-    sink = smtp_server.sink
-    assert len(sink) == 1
 
+    with SMTP(smtpd.hostname, smtpd.port):
+        assert mailer.send_messages(email)
+
+    assert len(smtpd.messages) == 1
+    message = smtpd.messages[0]
+    print(message)
+    assert message.get_content_type() == "text/plain"
+    assert message.get("subject") == "=?utf-8?q?Ol=C3=A9?="
 
-def test_notls():
-    mailer = SMTPMailer(host="127.0.0.1", port=SMTP_PORT, use_tls=True)
+
+def test_notls(smtpd):
+    mailer = SMTPMailer(host=smtpd.hostname, port=smtpd.port, use_tls=True)
     with pytest.raises(SMTPException):
-        mailer.open()
+        with SMTP(smtpd.hostname, smtpd.port):
+            mailer.open()
     mailer.close()
 
 
-def test_wrong_host():
-    mailer = SMTPMailer(host="123", port=SMTP_PORT, use_tls=False, timeout=0.5)
+def test_wrong_host(smtpd):
+    mailer = SMTPMailer(host="123", port=smtpd.port, use_tls=False, timeout=0.5)
     with pytest.raises(Exception):
-        mailer.open()
+        with SMTP(smtpd.hostname, smtpd.port):
+            mailer.open()
     mailer.close()
 
 
-def test_wrong_port():
-    mailer = SMTPMailer(host="127.0.0.1", port=3000, use_tls=False)
+def test_wrong_port(smtpd):
+    mailer = SMTPMailer(host=smtpd.hostname, port=3000, use_tls=False)
     with pytest.raises(Exception):
-        mailer.open()
+        with SMTP(smtpd.hostname, smtpd.port):
+            mailer.open()
     mailer.close()
 
 
-def test_fail_silently():
+def test_fail_silently(smtpd):
     mailer = SMTPMailer(
-        host="127.0.0.1", port=SMTP_PORT, use_tls=True, fail_silently=True
+        host=smtpd.hostname,
+        port=smtpd.port,
+        use_tls=True,
+        fail_silently=True,
     )
-    mailer.open()
+    with SMTP(smtpd.hostname, smtpd.port):
+        mailer.open()
     mailer.close()
 
     mailer = SMTPMailer(
-        host="123", port=SMTP_PORT, use_tls=False, fail_silently=True, timeout=0.5
+        host="123",
+        port=smtpd.port,
+        use_tls=False,
+        fail_silently=True,
+        timeout=0.5,
     )
-    mailer.open()
+    with SMTP(smtpd.hostname, smtpd.port):
+        mailer.open()
     mailer.close()
 
-    mailer = SMTPMailer(host="127.0.0.1", port=3000, use_tls=False, fail_silently=True)
-    mailer.open()
+    mailer = SMTPMailer(
+        host=smtpd.hostname,
+        port=3000,
+        use_tls=False,
+        fail_silently=True,
+    )
+    with SMTP(smtpd.hostname, smtpd.port):
+        mailer.open()
     mailer.close()
 
 
-def test_batch_too_many_recipients():
-    global smtp_server
-    smtp_server.flush_sink()
-
+def test_batch_too_many_recipients(smtpd):
     mailer = SMTPMailer(
-        host="127.0.0.1", port=SMTP_PORT, use_tls=False, max_recipients=200
+        host=smtpd.hostname,
+        port=smtpd.port,
+        use_tls=False,
+        max_recipients=200,
     )
     send_to = ["user{}@example.com".format(i) for i in range(1, 1501)]
     msg = EmailMessage("The Subject", "Content", "from@example.com", send_to)
 
-    assert mailer.send_messages(msg) == 1
-    sink = smtp_server.sink
-    assert len(sink) == 8
-
-    assert len(sink[0].get("to").split(",")) == 200
-    assert len(sink[1].get("to").split(",")) == 200
-    assert len(sink[2].get("to").split(",")) == 200
-    assert len(sink[3].get("to").split(",")) == 200
-    assert len(sink[4].get("to").split(",")) == 200
-    assert len(sink[5].get("to").split(",")) == 200
-    assert len(sink[6].get("to").split(",")) == 200
-    assert len(sink[7].get("to").split(",")) == 100
+    with SMTP(smtpd.hostname, smtpd.port):
+        assert mailer.send_messages(msg) == 1
+
+    assert len(smtpd.messages) == 8
+    assert len(smtpd.messages[0].get("to").split(",")) == 200
+    assert len(smtpd.messages[1].get("to").split(",")) == 200
+    assert len(smtpd.messages[2].get("to").split(",")) == 200
+    assert len(smtpd.messages[3].get("to").split(",")) == 200
+    assert len(smtpd.messages[4].get("to").split(",")) == 200
+    assert len(smtpd.messages[5].get("to").split(",")) == 200
+    assert len(smtpd.messages[6].get("to").split(",")) == 200
+    assert len(smtpd.messages[7].get("to").split(",")) == 100
diff --git a/tox.ini b/tox.ini
index decdac7..f1ae285 100755
--- a/tox.ini
+++ b/tox.ini
@@ -1,6 +1,6 @@
 [tox]
 skipsdist = True
-envlist = py36,py37,py38
+envlist = py37,py38,py39,py310,py311
 
 [testenv]
 skip_install = true