Allow messages with cc or bcc but no recipients.

Fixes #14.

pyramid_mailer/message.py

@@ -136,7 +136,7 @@ def validate(self):
         Checks if message is valid and raises appropriate exception.
         """
 
-        if not self.recipients:
+        if not (self.recipients or self.cc or self.bcc):
             raise InvalidMessage("No recipients have been added")
 
         if not self.body and not self.html:

pyramid_mailer/tests.py

@@ -158,6 +158,38 @@ def test_cc(self):
         response = msg.get_response()
         self.assert_("Cc: tosomeoneelse@example.com" in str(response))
 
+    def test_cc_without_recipients(self):
+
+        from pyramid_mailer.message import Message
+        from pyramid_mailer.mailer import Mailer
+
+        msg = Message(subject="testing",
+                      sender="sender@example.com",
+                      body="testing",
+                      cc=["tosomeoneelse@example.com"])
+        mailer = Mailer()
+        msgid = mailer.send(msg)
+        response = msg.get_response()
+
+        self.assertTrue("Cc: tosomeoneelse@example.com" in str(response))
+        self.assertTrue(msgid)
+
+    def test_bcc_without_recipients(self):
+
+        from pyramid_mailer.message import Message
+        from pyramid_mailer.mailer import Mailer
+
+        msg = Message(subject="testing",
+                      sender="sender@example.com",
+                      body="testing",
+                      bcc=["tosomeoneelse@example.com"])
+        mailer = Mailer()
+        msgid = mailer.send(msg)
+        response = msg.get_response()
+
+        self.assertFalse("Bcc: tosomeoneelse@example.com" in str(response))
+        self.assertTrue(msgid)
+
     def test_attach(self):
 
         from pyramid_mailer.message import Message