Add ability to disable sending of queued mails.

Fixes #14 for Zope 2.13.

CHANGES.txt

@@ -4,6 +4,9 @@ Changelog
 2.13.3 (unreleased)
 -------------------
 
+- Add ability to disable sending of queued mails. Details see README.txt.
+  (`#14 <https://github.com/zopefoundation/Products.MailHost/issues/14>`_)
+
 
 2.13.2 (2014-11-02)
 -------------------

README.txt

@@ -12,6 +12,9 @@ Email can optionally be encoded using Base64, Quoted-Printable or UUEncode
 encoding (though automatic body encoding will be applied if a character set is
 specified).
 
+Usage
+-----
+
 MailHost provides integration with the Zope transaction system and optional
 support for asynchronous mail delivery. Asynchronous mail delivery is
 implemented using a queue and a dedicated thread processing the queue. The
@@ -21,3 +24,10 @@ manage_restartQueueThread?action=start method through HTTP. There is currently
 no possibility to start the thread at Zope startup time.
 
 Supports TLS/SSL encryption (requires Python compiled with SSL support).
+
+Configuration
+-------------
+
+To force MailHost to only queue mails without sending them, activate queuing
+in the ZMI and set the environment variable ``MAILHOST_QUEUE_ONLY=1``.
+This could be helpful in a staging environment where mails should not be sent.

src/Products/MailHost/MailHost.py

@@ -13,6 +13,7 @@
 """SMTP mail objects
 """
 import logging
+import os
 from os.path import realpath
 import re
 from cStringIO import StringIO
@@ -338,7 +339,8 @@ def _send(self, mfrom, mto, messageText, immediate=False):
         else:
             if self.smtp_queue:
                 # Start queue processor thread, if necessary
-                self._startQueueProcessorThread()
+                if not os.environ.get('MAILHOST_QUEUE_ONLY', False):
+                    self._startQueueProcessorThread()
                 delivery = QueuedMailDelivery(self.smtp_queue_directory)
             else:
                 delivery = DirectMailDelivery(self._makeMailer())

src/Products/MailHost/tests/testMailHost.py

@@ -13,8 +13,14 @@
 """MailHost unit tests.
 """
 
-import unittest
 from email import message_from_string
+import os.path
+import shutil
+import six
+import tempfile
+import transaction
+import unittest
+import zope.sendmail.maildir
 
 from Products.MailHost.MailHost import MailHost
 from Products.MailHost.MailHost import MailHostError, _mungeHeaders
@@ -641,7 +647,67 @@ def testSendMultiPartMixedMessage(self):
         self.assertEqual(mailhost.sent, msg)
 
 
+class QueueingDummyMailHost(MailHost):
+    """Dummy mail host implementation which supports queueing."""
+
+    meta_type = 'Queueing Dummy Mail Host'
+
+    def __init__(self, id, smtp_queue_directory):
+        self.id = id
+        self.smtp_queue = True
+        self.smtp_queue_directory = smtp_queue_directory
+        self.started_queue_processor_thread = False
+
+    def _startQueueProcessorThread(self):
+        self.started_queue_processor_thread = True
+
+
+class TestMailHostQueuing(unittest.TestCase):
+
+    smtp_queue_directory = None
+
+    def _getTargetClass(self):
+        return QueueingDummyMailHost
+
+    def _makeOne(self, *args):
+        self.tmpdir = tempfile.mkdtemp(suffix='MailHostTests')
+        self.smtp_queue_directory = os.path.join(self.tmpdir, 'queue')
+        return self._getTargetClass()(
+            *args, smtp_queue_directory=self.smtp_queue_directory)
+
+    def _callFUT(self):
+        mh = self._makeOne('MailHost')
+        mh.send(
+            'Nice to see you!',
+            mto='user@example.com',
+            mfrom='zope@example.com',
+            subject='Hello world')
+        transaction.commit()
+        return mh
+
+    def tearDown(self):
+        super(TestMailHostQueuing, self).tearDown()
+        shutil.rmtree(self.tmpdir, ignore_errors=True)
+
+    def testStartQueueProcessorThread(self):
+        mh = self._callFUT()
+        self.assertTrue(mh.started_queue_processor_thread)
+        md = zope.sendmail.maildir.Maildir(self.smtp_queue_directory)
+        self.assertEqual(len(list(md)), 1)
+
+    def testNotStartQueueProcessorThread(self):
+        os.environ['MAILHOST_QUEUE_ONLY'] = '1'
+        try:
+            mh = self._callFUT()
+        finally:
+            del os.environ['MAILHOST_QUEUE_ONLY']
+        self.assertFalse(mh.started_queue_processor_thread)
+        md = zope.sendmail.maildir.Maildir(self.smtp_queue_directory)
+        self.assertEqual(len(list(md)), 1)
+
+
 def test_suite():
     suite = unittest.TestSuite()
     suite.addTest(unittest.makeSuite(TestMailHost))
+    suite.addTest(unittest.makeSuite(TestMailHostQueuing))
     return suite