diff --git a/logbook/handlers.py b/logbook/handlers.py
index 82e518f..5f66978 100644
--- a/logbook/handlers.py
+++ b/logbook/handlers.py
@@ -20,6 +20,7 @@ try:
 except ImportError:
     from sha import new as sha1
 import traceback
+import collections
 from datetime import datetime, timedelta
 from collections import deque
 from textwrap import dedent
@@ -1014,14 +1015,42 @@ class MailHandler(Handler, StringFormatterHandlerMixin,
 
     The default timedelta is 60 seconds (one minute).
 
-    The mail handler is sending mails in a blocking manner.  If you are not
+    The mail handler sends mails in a blocking manner.  If you are not
     using some centralized system for logging these messages (with the help
     of ZeroMQ or others) and the logging system slows you down you can
     wrap the handler in a :class:`logbook.queues.ThreadedWrapperHandler`
     that will then send the mails in a background thread.
 
+    `server_addr` can be a tuple of host and port, or just a string containing
+    the host to use the default port (25, or 465 if connecting securely.)
+
+    `credentials` can be a tuple or dictionary of arguments that will be passed
+    to :py:meth:`smtplib.SMTP.login`.
+
+    `secure` can be a tuple, dictionary, or boolean. As a boolean, this will
+    simply enable or disable a secure connection. The tuple is unpacked as
+    parameters `keyfile`, `certfile`. As a dictionary, `secure` should contain
+    those keys. For backwards compatibility, ``secure=()`` will enable a secure
+    connection. If `starttls` is enabled (default), these parameters will be
+    passed to :py:meth:`smtplib.SMTP.starttls`, otherwise
+    :py:class:`smtplib.SMTP_SSL`.
+
+
     .. versionchanged:: 0.3
        The handler supports the batching system now.
+
+    .. versionadded:: 1.0
+       `starttls` parameter added to allow disabling STARTTLS for SSL
+       connections.
+
+    .. versionchanged:: 1.0
+       If `server_addr` is a string, the default port will be used.
+
+    .. versionchanged:: 1.0
+       `credentials` parameter can now be a dictionary of keyword arguments.
+
+    .. versionchanged:: 1.0
+       `secure` can now be a dictionary or boolean in addition to to a tuple.
     """
     default_format_string = MAIL_FORMAT_STRING
     default_related_format_string = MAIL_RELATED_FORMAT_STRING
@@ -1039,7 +1068,7 @@ class MailHandler(Handler, StringFormatterHandlerMixin,
                  server_addr=None, credentials=None, secure=None,
                  record_limit=None, record_delta=None, level=NOTSET,
                  format_string=None, related_format_string=None,
-                 filter=None, bubble=False):
+                 filter=None, bubble=False, starttls=True):
         Handler.__init__(self, level, filter, bubble)
         StringFormatterHandlerMixin.__init__(self, format_string)
         LimitingHandlerMixin.__init__(self, record_limit, record_delta)
@@ -1054,6 +1083,7 @@ class MailHandler(Handler, StringFormatterHandlerMixin,
         if related_format_string is None:
             related_format_string = self.default_related_format_string
         self.related_format_string = related_format_string
+        self.starttls = starttls
 
     def _get_related_format_string(self):
         if isinstance(self.related_formatter, StringFormatter):
@@ -1148,20 +1178,63 @@ class MailHandler(Handler, StringFormatterHandlerMixin,
         """Returns an SMTP connection.  By default it reconnects for
         each sent mail.
         """
-        from smtplib import SMTP, SMTP_PORT, SMTP_SSL_PORT
+        from smtplib import SMTP, SMTP_SSL, SMTP_PORT, SMTP_SSL_PORT
         if self.server_addr is None:
             host = '127.0.0.1'
             port = self.secure and SMTP_SSL_PORT or SMTP_PORT
         else:
-            host, port = self.server_addr
-        con = SMTP()
-        con.connect(host, port)
+            try:
+                host, port = self.server_addr
+            except ValueError:
+                # If server_addr is a string, the tuple unpacking will raise
+                # ValueError, and we can use the default port.
+                host = self.server_addr
+                port = self.secure and SMTP_SSL_PORT or SMTP_PORT
+
+        # Previously, self.secure was passed as con.starttls(*self.secure). This
+        # meant that starttls couldn't be used without a keyfile and certfile
+        # unless an empty tuple was passed. See issue #94.
+        #
+        # The changes below allow passing:
+        # - secure=True for secure connection without checking identity.
+        # - dictionary with keys 'keyfile' and 'certfile'.
+        # - tuple to be unpacked to variables keyfile and certfile.
+        # - secure=() equivalent to secure=True for backwards compatibility.
+        # - secure=False equivalent to secure=None to disable.
+        if isinstance(self.secure, collections.Mapping):
+            keyfile = self.secure.get('keyfile', None)
+            certfile = self.secure.get('certfile', None)
+        elif isinstance(self.secure, collections.Iterable):
+            # Allow empty tuple for backwards compatibility
+            if len(self.secure) == 0:
+                keyfile = certfile = None
+            else:
+                keyfile, certfile = self.secure
+        else:
+            keyfile = certfile = None
+
+        # Allow starttls to be disabled by passing starttls=False.
+        if not self.starttls and self.secure:
+            con = SMTP_SSL(host, port, keyfile=keyfile, certfile=certfile)
+        else:
+            con = SMTP(host, port)
+
         if self.credentials is not None:
-            if self.secure is not None:
+            secure = self.secure
+            if self.starttls and secure is not None and secure is not False:
                 con.ehlo()
-                con.starttls(*self.secure)
+                con.starttls(keyfile=keyfile, certfile=certfile)
                 con.ehlo()
-            con.login(*self.credentials)
+
+            # Allow credentials to be a tuple or dict.
+            if isinstance(self.credentials, collections.Mapping):
+                credentials_args = ()
+                credentials_kwargs = self.credentials
+            else:
+                credentials_args = self.credentials
+                credentials_kwargs = dict()
+
+            con.login(*credentials_args, **credentials_kwargs)
         return con
 
     def close_connection(self, con):
@@ -1175,7 +1248,7 @@ class MailHandler(Handler, StringFormatterHandlerMixin,
             pass
 
     def deliver(self, msg, recipients):
-        """Delivers the given message to a list of recpients."""
+        """Delivers the given message to a list of recipients."""
         con = self.get_connection()
         try:
             con.sendmail(self.from_addr, recipients, msg.as_string())
@@ -1227,7 +1300,7 @@ class GMailHandler(MailHandler):
 
     def __init__(self, account_id, password, recipients, **kw):
         super(GMailHandler, self).__init__(
-            account_id, recipients, secure=(),
+            account_id, recipients, secure=True,
             server_addr=("smtp.gmail.com", 587),
             credentials=(account_id, password), **kw)
 
diff --git a/setup.py b/setup.py
index 26df542..bdb9b00 100644
--- a/setup.py
+++ b/setup.py
@@ -158,6 +158,10 @@ with open(version_file_path) as version_file:
 
 extras_require = dict()
 extras_require['test'] = set(['pytest', 'pytest-cov'])
+
+if sys.version_info[:2] < (3, 3):
+    extras_require['test'] |= set(['mock'])
+
 extras_require['dev'] = set(['cython']) | extras_require['test']
 
 extras_require['execnet'] = set(['execnet>=1.0.9'])

SMTP Handler STARTTLS
Due to the lack of documentation on this handler it took a little digging to work out how to get it to work...

One thing that confused me was the "secure" argument. Python SMTPLib starttls() accepts two optional values: a keyfile and certfile - but these are only required for *checking* the identity. If neither are specified then SMTPLib will still try establish an encrypted connection but without checking the identity. If you do not specify an argument to Logbook, it will not attempt to establish an encrypted connection at all.

So, if you want a tls connection to the SMTP server but don't care about checking the identity you can do `secure = []` which will pass the `if self.secure is not None`, however if you do `secure = True` you will get an error because you cannot unpack a boolean! (as logbook populates the arguments using: `conn.starttls(*self.secure)`).

It'd help if the documentation explained the arguments for the mail handlers.
diff --git a/tests/test_mail_handler.py b/tests/test_mail_handler.py
index babc4e2..fd7730b 100644
--- a/tests/test_mail_handler.py
+++ b/tests/test_mail_handler.py
@@ -7,6 +7,11 @@ from logbook.helpers import u
 
 from .utils import capturing_stderr_context, make_fake_mail_handler
 
+try:
+    from unittest.mock import Mock, call, patch
+except ImportError:
+    from mock import Mock, call, patch
+
 __file_without_pyc__ = __file__
 if __file_without_pyc__.endswith('.pyc'):
     __file_without_pyc__ = __file_without_pyc__[:-1]
@@ -104,3 +109,126 @@ def test_group_handler_mail_combo(activation_strategy, logger):
     assert len(related) == 2
     assert re.search('Message type:\s+WARNING', related[0])
     assert re.search('Message type:\s+DEBUG', related[1])
+
+
+def test_mail_handler_arguments():
+    with patch('smtplib.SMTP', autospec=True) as mock_smtp:
+
+        # Test the mail handler with supported arguments before changes to
+        # secure, credentials, and starttls
+        mail_handler = logbook.MailHandler(
+            from_addr='from@example.com',
+            recipients='to@example.com',
+            server_addr=('server.example.com', 465),
+            credentials=('username', 'password'),
+            secure=('keyfile', 'certfile'))
+
+        mail_handler.get_connection()
+
+        assert mock_smtp.call_args == call('server.example.com', 465)
+        assert mock_smtp.method_calls[1] == call().starttls(
+            keyfile='keyfile', certfile='certfile')
+        assert mock_smtp.method_calls[3] == call().login('username', 'password')
+
+        # Test secure=()
+        mail_handler = logbook.MailHandler(
+            from_addr='from@example.com',
+            recipients='to@example.com',
+            server_addr=('server.example.com', 465),
+            credentials=('username', 'password'),
+            secure=())
+
+        mail_handler.get_connection()
+
+        assert mock_smtp.call_args == call('server.example.com', 465)
+        assert mock_smtp.method_calls[5] == call().starttls(
+            certfile=None, keyfile=None)
+        assert mock_smtp.method_calls[7] == call().login('username', 'password')
+
+        # Test implicit port with string server_addr, dictionary credentials,
+        # dictionary secure.
+        mail_handler = logbook.MailHandler(
+            from_addr='from@example.com',
+            recipients='to@example.com',
+            server_addr='server.example.com',
+            credentials={'user': 'username', 'password': 'password'},
+            secure={'certfile': 'certfile2', 'keyfile': 'keyfile2'})
+
+        mail_handler.get_connection()
+
+        assert mock_smtp.call_args == call('server.example.com', 465)
+        assert mock_smtp.method_calls[9] == call().starttls(
+            certfile='certfile2', keyfile='keyfile2')
+        assert mock_smtp.method_calls[11] == call().login(
+            user='username', password='password')
+
+        # Test secure=True
+        mail_handler = logbook.MailHandler(
+            from_addr='from@example.com',
+            recipients='to@example.com',
+            server_addr=('server.example.com', 465),
+            credentials=('username', 'password'),
+            secure=True)
+
+        mail_handler.get_connection()
+
+        assert mock_smtp.call_args == call('server.example.com', 465)
+        assert mock_smtp.method_calls[13] == call().starttls(
+            certfile=None, keyfile=None)
+        assert mock_smtp.method_calls[15] == call().login('username', 'password')
+        assert len(mock_smtp.method_calls) == 16
+
+        # Test secure=False
+        mail_handler = logbook.MailHandler(
+            from_addr='from@example.com',
+            recipients='to@example.com',
+            server_addr=('server.example.com', 465),
+            credentials=('username', 'password'),
+            secure=False)
+
+        mail_handler.get_connection()
+
+        # starttls not called because we check len of method_calls before and
+        # after this test.
+        assert mock_smtp.call_args == call('server.example.com', 465)
+        assert mock_smtp.method_calls[16] == call().login('username', 'password')
+        assert len(mock_smtp.method_calls) == 17
+
+    with patch('smtplib.SMTP_SSL', autospec=True) as mock_smtp_ssl:
+        # Test starttls=False
+        mail_handler = logbook.MailHandler(
+            from_addr='from@example.com',
+            recipients='to@example.com',
+            server_addr='server.example.com',
+            credentials={'user': 'username', 'password': 'password'},
+            secure={'certfile': 'certfile', 'keyfile': 'keyfile'},
+            starttls=False)
+
+        mail_handler.get_connection()
+
+        assert mock_smtp_ssl.call_args == call(
+            'server.example.com', 465, keyfile='keyfile', certfile='certfile')
+        assert mock_smtp_ssl.method_calls[0] == call().login(
+            user='username', password='password')
+
+        # Test starttls=False with secure=True
+        mail_handler = logbook.MailHandler(
+            from_addr='from@example.com',
+            recipients='to@example.com',
+            server_addr='server.example.com',
+            credentials={'user': 'username', 'password': 'password'},
+            secure=True,
+            starttls=False)
+
+        mail_handler.get_connection()
+
+        assert mock_smtp_ssl.call_args == call(
+            'server.example.com', 465, keyfile=None, certfile=None)
+        assert mock_smtp_ssl.method_calls[1] == call().login(
+            user='username', password='password')
+
+
+
+
+
+

pip install -e .[dev]
parse_log_pytest
pytest
pytest Cython
apt-get update apt-get install -y gcc
3.9
pytest --no-header -rA --tb=line --color=no -p no:cacheprovider -W ignore::DeprecationWarning
coverage==7.8.0
Cython==3.0.12
exceptiongroup @ file:///croot/exceptiongroup_1706031385326/work
iniconfig @ file:///home/linux1/recipes/ci/iniconfig_1610983019677/work
-e git+https://github.com/getlogbook/logbook.git@1d999a784d0d8f5f7423f25c684cc1100843ccc5#egg=Logbook
packaging @ file:///croot/packaging_1734472117206/work
pluggy @ file:///croot/pluggy_1733169602837/work
pytest @ file:///croot/pytest_1738938843180/work
pytest-cov==6.0.0
tomli @ file:///opt/conda/conda-bld/tomli_1657175507142/work

name: logbook
channels:
  - defaults
  - https://repo.anaconda.com/pkgs/main
  - https://repo.anaconda.com/pkgs/r
  - conda-forge
dependencies:
  - _libgcc_mutex=0.1=main
  - _openmp_mutex=5.1=1_gnu
  - ca-certificates=2025.2.25=h06a4308_0
  - exceptiongroup=1.2.0=py39h06a4308_0
  - iniconfig=1.1.1=pyhd3eb1b0_0
  - ld_impl_linux-64=2.40=h12ee557_0
  - libffi=3.4.4=h6a678d5_1
  - libgcc-ng=11.2.0=h1234567_1
  - libgomp=11.2.0=h1234567_1
  - libstdcxx-ng=11.2.0=h1234567_1
  - ncurses=6.4=h6a678d5_0
  - openssl=3.0.16=h5eee18b_0
  - packaging=24.2=py39h06a4308_0
  - pip=25.0=py39h06a4308_0
  - pluggy=1.5.0=py39h06a4308_0
  - pytest=8.3.4=py39h06a4308_0
  - python=3.9.21=he870216_1
  - readline=8.2=h5eee18b_0
  - setuptools=75.8.0=py39h06a4308_0
  - sqlite=3.45.3=h5eee18b_0
  - tk=8.6.14=h39e8969_0
  - tomli=2.0.1=py39h06a4308_0
  - tzdata=2025a=h04d1e81_0
  - wheel=0.45.1=py39h06a4308_0
  - xz=5.6.4=h5eee18b_1
  - zlib=1.2.13=h5eee18b_1
  - pip:
      - coverage==7.8.0
      - cython==3.0.12
      - pytest-cov==6.0.0
prefix: /opt/conda/envs/logbook

tests/test_mail_handler.py::test_mail_handler_arguments
tests/test_mail_handler.py::test_mail_handler[ContextEnteringStrategy] tests/test_mail_handler.py::test_mail_handler[PushingStrategy] tests/test_mail_handler.py::test_mail_handler_batching[ContextEnteringStrategy] tests/test_mail_handler.py::test_mail_handler_batching[PushingStrategy] tests/test_mail_handler.py::test_group_handler_mail_combo[ContextEnteringStrategy] tests/test_mail_handler.py::test_group_handler_mail_combo[PushingStrategy]
logbook/handlers.py setup.py
logbook/handlers.py setup.py