diff --git a/mandrill.cabal b/mandrill.cabal
--- a/mandrill.cabal
+++ b/mandrill.cabal
@@ -1,5 +1,5 @@
 name:                mandrill
-version:             0.5.3.6
+version:             0.5.4.0
 synopsis:            Library for interfacing with the Mandrill JSON API
 description:         Pure Haskell client for the Mandrill JSON API
 license:             MIT
diff --git a/src/Network/API/Mandrill.hs b/src/Network/API/Mandrill.hs
--- a/src/Network/API/Mandrill.hs
+++ b/src/Network/API/Mandrill.hs
@@ -14,6 +14,7 @@
   , newTextMessage
   , newHtmlMessage
   , newTemplateMessage
+  , newTemplateMessage'
   , liftIO
 
   -- * Appendix: Example Usage
@@ -58,12 +59,12 @@
 -- | Builds an empty message, given only the email of the sender and
 -- the emails of the receiver. Please note that the "Subject" will be empty,
 -- so you need to use either @newTextMessage@ or @newHtmlMessage@ to populate it.
-emptyMessage :: EmailAddress -> [EmailAddress] -> MandrillMessage
+emptyMessage :: Maybe EmailAddress -> [EmailAddress] -> MandrillMessage
 emptyMessage f t = MandrillMessage {
    _mmsg_html = mempty
  , _mmsg_text = Nothing
- , _mmsg_subject = T.empty
- , _mmsg_from_email = (MandrillEmail f)
+ , _mmsg_subject = Nothing
+ , _mmsg_from_email = MandrillEmail <$> f
  , _mmsg_from_name = Nothing
  , _mmsg_to = map newRecipient t
  , _mmsg_headers = H.empty
@@ -106,7 +107,7 @@
                -- ^ The HTML body
                -> MandrillMessage
 newHtmlMessage f t subj html = let body = mkMandrillHtml html in
-  (emptyMessage f t) { _mmsg_html = body, _mmsg_subject = subj }
+  (emptyMessage (Just f) t) { _mmsg_html = body, _mmsg_subject = Just subj }
 
 --------------------------------------------------------------------------------
 -- | Create a new template message (no HTML).
@@ -117,9 +118,18 @@
                    -> T.Text
                    -- ^ Subject
                    -> MandrillMessage
-newTemplateMessage f t subj = (emptyMessage f t) { _mmsg_subject = subj }
+newTemplateMessage f t subj = (emptyMessage (Just f) t) { _mmsg_subject = Just subj }
 
 --------------------------------------------------------------------------------
+-- | Create a new template message (no HTML) with recipient addresses only.
+-- This function is preferred when the template being used has the sender 
+-- address and subject already configured in the Mandrill server.
+newTemplateMessage' :: [EmailAddress]
+                    -- ^ Receivers email
+                    -> MandrillMessage
+newTemplateMessage' = emptyMessage Nothing
+
+--------------------------------------------------------------------------------
 -- | Create a new textual message. By default Mandrill doesn't require you
 -- to specify the @mmsg_text@ when sending out the JSON Payload, and this
 -- function ensure it will be present.
@@ -133,10 +143,10 @@
                -- ^ The body, as normal text.
                -> MandrillMessage
 newTextMessage f t subj txt = let body = unsafeMkMandrillHtml txt in
-  (emptyMessage f t) {
+  (emptyMessage (Just f) t) {
        _mmsg_html = body
      , _mmsg_text = Just txt
-     , _mmsg_subject = subj
+     , _mmsg_subject = Just subj
      }
 
 
diff --git a/src/Network/API/Mandrill/HTTP.hs b/src/Network/API/Mandrill/HTTP.hs
--- a/src/Network/API/Mandrill/HTTP.hs
+++ b/src/Network/API/Mandrill/HTTP.hs
@@ -18,7 +18,7 @@
                    -> IO (MandrillResponse a)
 toMandrillResponse ep rq mbMgr = do
   let fullUrl = mandrillUrl <> toUrl ep
-  rq' <- parseUrl (T.unpack fullUrl)
+  rq' <- parseRequest (T.unpack fullUrl)
   let headers = [(hContentType, "application/json")]
   let jsonBody = encode rq
   let req = rq' {
diff --git a/src/Network/API/Mandrill/Types.hs b/src/Network/API/Mandrill/Types.hs
--- a/src/Network/API/Mandrill/Types.hs
+++ b/src/Network/API/Mandrill/Types.hs
@@ -252,9 +252,9 @@
    -- ^ The full HTML content to be sent
  , _mmsg_text                      :: Maybe T.Text
    -- ^ Optional full text content to be sent
- , _mmsg_subject                   :: !T.Text
+ , _mmsg_subject                   :: !(Maybe T.Text)
    -- ^ The message subject
- , _mmsg_from_email                :: MandrillEmail
+ , _mmsg_from_email                :: Maybe MandrillEmail
    -- ^ The sender email address
  , _mmsg_from_name                 :: Maybe T.Text
    -- ^ Optional from name to be used
@@ -336,8 +336,8 @@
 instance Arbitrary MandrillMessage where
   arbitrary = MandrillMessage <$> arbitrary
                               <*> pure Nothing
-                              <*> pure "Test Subject"
-                              <*> pure (MandrillEmail . fromJust $ emailAddress "sender@example.com")
+                              <*> pure (Just "Test Subject")
+                              <*> pure (MandrillEmail <$> emailAddress "sender@example.com")
                               <*> pure Nothing
                               <*> resize 2 arbitrary
                               <*> pure H.empty
@@ -389,6 +389,6 @@
 
 instance FromJSON MandrillDate where
   parseJSON = withText "MandrillDate" $ \t ->
-      case timeParse defaultTimeLocale "%Y-%m-%d %I:%M:%S%Q" (T.unpack t) of
+      case timeParse defaultTimeLocale "%Y-%m-%d %H:%M:%S%Q" (T.unpack t) of
         Just d -> pure $ MandrillDate d
         _      -> fail "could not parse Mandrill date"