Minor alterations to @yellowcap's pull request submission:

* Using a query parameter argument (rather than the entire query string)
  to specify the folder into which e-mail messages should be archived.
* Duplicating the IMAP tests; this could probably be a bit more simply
  done, but we'll at least be verifying both archived and non-archived
  use cases.
* Simplifying some aspects of the documentation to include references
  to this new feature.

django_mailbox/tests/test_transports.py

@@ -6,6 +6,47 @@ from django_mailbox.transports import ImapTransport, Pop3Transport
 
 
 class TestImapTransport(EmailMessageTestCase):
+    def setUp(self):
+        self.arbitrary_hostname = 'one.two.three'
+        self.arbitrary_port = 100
+        self.ssl = False
+        self.transport = ImapTransport(
+            self.arbitrary_hostname,
+            self.arbitrary_port,
+            self.ssl
+        )
+        self.transport.server = None
+        super(TestImapTransport, self).setUp()
+
+    def test_get_email_message(self):
+        with mock.patch.object(self.transport, 'server') as server:
+            server.search.return_value = (
+                'OK',
+                [
+                    'One',  # This is totally arbitrary
+                ]
+            )
+            server.fetch.return_value = (
+                'OK',
+                [
+                    [
+                        '1 (RFC822 {8190}',  # Wat?
+                        self._get_email_as_text('generic_message.eml')
+                    ],
+                    ')',
+                ]
+            )
+            actual_messages = list(self.transport.get_message())
+
+        self.assertEqual(len(actual_messages), 1)
+
+        actual_message = actual_messages[0]
+        expected_message = self._get_email_object('generic_message.eml')
+
+        self.assertEqual(expected_message, actual_message)
+
+
+class TestImapArchivedTransport(EmailMessageTestCase):
     def setUp(self):
         self.arbitrary_hostname = 'one.two.three'
         self.arbitrary_port = 100
@@ -18,7 +59,7 @@ class TestImapTransport(EmailMessageTestCase):
             self.archive
         )
         self.transport.server = None
-        super(TestImapTransport, self).setUp()
+        super(TestImapArchivedTransport, self).setUp()
 
     def test_get_email_message(self):
         with mock.patch.object(self.transport, 'server') as server: