Encode message to bytes in smtp backend

emails/backend/smtp/backend.py

@@ -91,14 +91,14 @@ def _send(self, **kwargs):
         response = None
         try:
             client = self.get_client()
-        except IOError as exc:
-            response = self.make_response(exception=SMTPConnectNetworkError.from_ioerror(exc))
-            if not self.fail_silently:
-                raise
         except smtplib.SMTPException as exc:
             response = self.make_response(exception=exc)
             if not self.fail_silently:
                 raise
+        except IOError as exc:
+            response = self.make_response(exception=SMTPConnectNetworkError.from_ioerror(exc))
+            if not self.fail_silently:
+                raise
 
         if response:
             if not self.fail_silently:
@@ -119,7 +119,7 @@ def sendmail(self, from_addr, to_addrs, msg, mail_options=None, rcpt_options=Non
 
         response = send(from_addr=from_addr,
                         to_addrs=to_addrs,
-                        msg=msg.as_string(),
+                        msg=msg.as_bytes(),
                         mail_options=mail_options or self.mail_options,
                         rcpt_options=rcpt_options)
 

emails/message.py

@@ -332,15 +332,21 @@ def as_string(self, message_cls=None):
 
         Note: this method costs one less message-to-string conversions
         for dkim in compare to self.as_message().as_string()
-
-        Changes:
-        v0.4.2: now returns bytes, not native string
         """
         r = to_native(self.build_message(message_cls=message_cls).as_string())
         if self._signer:
             r = self.sign_string(r)
         return r
 
+    def as_bytes(self, message_cls=None):
+        """
+        Returns message as bytes.
+        """
+        r = self.build_message(message_cls=message_cls).as_bytes()
+        if self._signer:
+            r = self.sign_string(r)
+        return r
+
 
 class MessageSendMixin(object):
 
@@ -461,6 +467,12 @@ def sign_string(self, message_string):
         """
         return self._signer.sign_message_string(message_string)
 
+    def sign_bytes(self, message_bytes):
+        """
+        Add sign header to message-as-a-string
+        """
+        return self._signer.sign_message_bytes(message_bytes)
+
 
 class Message(MessageSendMixin, MessageTransformerMixin, MessageSignMixin, MessageBuildMixin, BaseMessage):
     """

emails/signers.py

@@ -40,7 +40,6 @@ def __init__(self, selector, domain, key=None, ignore_sign_errors=False, **kwarg
                                   'selector': to_bytes(selector)})
 
     def get_sign_string(self, message):
-
         try:
             # pydkim module parses message and privkey on each signing
             # this is not optimal for mass operations
@@ -52,6 +51,9 @@ def get_sign_string(self, message):
             else:
                 raise
 
+    def get_sign_bytes(self, message):
+        return self.get_sign_string(message)
+
     def get_sign_header(self, message):
         # pydkim returns string, so we should split
         s = self.get_sign_string(message)
@@ -87,3 +89,9 @@ def sign_message_string(self, message_string):
         s = self.get_sign_string(to_bytes(message_string))
         return s and to_native(s) + message_string or message_string
 
+    def sign_message_bytes(self, message_bytes):
+        """
+        Insert DKIM header to message bytes
+        """
+        s = self.get_sign_bytes(message_bytes)
+        return s and to_bytes(s) + message_bytes or message_bytes