diff --git a/Network/Smtp/Session.hs b/Network/Smtp/Session.hs
--- a/Network/Smtp/Session.hs
+++ b/Network/Smtp/Session.hs
@@ -40,11 +40,12 @@
 hello domain = do
     mailPutLn ["EHLO ", domain]
     SmtpResponse code msgs <- nextResponse
-    let exts = S.fromList . catMaybes .
-               L.map stringToExtension . V.toList $ msgs
+    let exts = S.fromList . catMaybes . L.map stringToExtension .
+               L.drop 1 . V.toList $ msgs
 
     case code of
       250 -> lift $ modify (\cfg -> cfg { mailExtensions = exts })
+             >> liftIO (print exts)
       500 -> tryHelo
       502 -> tryHelo
       554 -> tryHelo
diff --git a/Network/Smtp/Tools.hs b/Network/Smtp/Tools.hs
--- a/Network/Smtp/Tools.hs
+++ b/Network/Smtp/Tools.hs
@@ -7,7 +7,7 @@
 --
 -- Helper functions and types.
 
-{-# LANGUAGE ScopedTypeVariables #-}
+{-# LANGUAGE OverloadedStrings, ScopedTypeVariables #-}
 
 module Network.Smtp.Tools
     ( enumHandleTimeout,
@@ -23,45 +23,19 @@
 
 import qualified Data.ByteString as B
 import qualified Data.ByteString.Char8 as BC
+import qualified Data.Set as S
 import qualified Data.Vector as V
 import Control.ContStuff as Cont
 import Data.Enumerator as E
-import Data.Enumerator.Binary as EB
 import Data.Enumerator.List as EL
 import Data.ByteString (ByteString)
 import Data.List as L
+import Data.Maybe
 import Data.Vector (Vector)
-import Data.Word
+import Network.NetLines
 import Network.Smtp.Types
-import System.IO
-import System.IO.Error as IOErr
 
 
--- | Enumerate from a handle with the given buffer size (first argument)
--- and timeout in milliseconds (second argument).  If the timeout is
--- exceeded an exception is thrown via 'throwError'.
-
-enumHandleTimeout :: forall b m. MonadIO m =>
-                     Int -> Int -> Handle -> Enumerator ByteString m b
-enumHandleTimeout bufSize timeout h = loop
-    where
-    loop :: Enumerator ByteString m b
-    loop (Continue k) = do
-          mHaveInput <- liftIO $ IOErr.try (hWaitForInput h timeout)
-          case mHaveInput of
-            Left err
-                | isEOFError err -> continue k
-                | otherwise      -> throwError err
-            Right False -> throwError $ userError "Handle timed out"
-            Right True  -> do
-                mStr <- liftIO $ IOErr.try (B.hGetNonBlocking h bufSize)
-                str <- either throwError return mStr
-                if B.null str
-                  then continue k
-                  else k (Chunks [str]) >>== loop
-    loop step = returnI step
-
-
 -- | Format a 'Vector' of 'ByteString' messages from an 'SmtpResponse'
 -- for output.
 
@@ -69,48 +43,6 @@
 formatMsgs = BC.unpack . BC.unwords . V.toList
 
 
--- | Savely read a line with the given maximum length.  If a longer line
--- is enumerated, the excess data is dropped in constant space.  Returns
--- 'Nothing' on EOF.
-
-netLine :: forall m r. Monad m => Int -> MaybeT r (Iteratee ByteString m) ByteString
-netLine n =
-    lift (EB.dropWhile isEol) >> netLine' n
-
-    where
-    isEol :: Word8 -> Bool
-    isEol 10 = True
-    isEol 13 = True
-    isEol _  = False
-
-    isNotEol :: Word8 -> Bool
-    isNotEol = not . isEol
-
-    netLine' :: Int -> MaybeT r (Iteratee ByteString m) ByteString
-    netLine' 0 = B.empty <$ lift (EB.dropWhile isNotEol)
-    netLine' n = do
-        c <- liftF EB.head
-        if isNotEol c
-          then B.cons c <$> netLine' (n-1)
-          else return B.empty
-
-
--- | Convert a stream of bytes to a stream of lines with the given
--- maximum length.  Longer lines are silently truncated in constant
--- space.
-
-netLines :: forall b m. Monad m => Int -> Enumeratee ByteString ByteString m b
-netLines maxLen = loop
-    where
-    loop :: Enumeratee ByteString ByteString m b
-    loop (Continue k) = do
-        mLine <- evalMaybeT $ netLine maxLen
-        case mLine of
-          Just line -> k (Chunks [line]) >>== loop
-          Nothing   -> k EOF >>== loop
-    loop step = return step
-
-
 -- | Read a three digit SMTP response code.
 
 readRespCode :: ByteString -> Maybe Integer
@@ -217,4 +149,13 @@
 -- extension is known.
 
 stringToExtension :: ByteString -> Maybe Extension
-stringToExtension _ = Nothing
+stringToExtension str =
+    case BC.words str of
+      "AUTH" : methods ->
+          Just . AuthExt . S.fromList . catMaybes . L.map authMethod $ methods
+
+      _ -> Nothing
+
+    where
+    authMethod :: ByteString -> Maybe AuthMethod
+    authMethod _ = Nothing
diff --git a/Network/Smtp/Types.hs b/Network/Smtp/Types.hs
--- a/Network/Smtp/Types.hs
+++ b/Network/Smtp/Types.hs
@@ -15,8 +15,11 @@
       MailT,
       StringMailT,
 
-      -- * Other types
+      -- * SMTP service extensions
       Extension(..),
+      AuthMethod(..),
+
+      -- * Other types
       MailConfig(..),
       SmtpCommand(..),
       SmtpException(..),
@@ -35,11 +38,18 @@
 import Text.Printf
 
 
+-- | Authentication methods for the SMTP authentication extension.
+
+data AuthMethod
+    = AuthMethod  -- ^ We don't know any authentication methods yet.
+    deriving (Eq, Ord, Read, Show)
+
+
 -- | SMTP service extension.
 
 data Extension
-    = Extension  -- ^ We don't support any extensions yet.
-    deriving (Eq, Ord)
+    = AuthExt (Set AuthMethod)  -- ^ Authentication extension.
+    deriving (Eq, Ord, Read, Show)
 
 
 -- | The 'MailT' monad transformer encapsulates an SMTP session.
diff --git a/ismtp.cabal b/ismtp.cabal
--- a/ismtp.cabal
+++ b/ismtp.cabal
@@ -1,5 +1,5 @@
 Name:          ismtp
-Version:       2.0.0
+Version:       2.0.1
 Category:      Network
 Synopsis:      Advanced ESMTP library
 Maintainer:    Ertugrul Söylemez <es@ertes.de>
@@ -24,6 +24,7 @@
         dnscache >= 1.0.1,
         enumerator >= 0.4.7,
         monad-peel >= 0.1,
+        netlines >= 0.1.0,
         network >= 2.2.1.7,
         unix >= 2.4.0.2,
         vector >= 0.7.0.1