src/DNS.hs

   1 module DNS ( lookup_mxs )
   2 where
   3
   4 import Network.DNS (
   5   Domain,
   6   defaultResolvConf,
   7   lookupMX,
   8   makeResolvSeed,
   9   withResolver )
  10
  11
  12 -- | Retrieve all MX records for the given domain. This is somewhat
  13 --   inefficient, since we create the resolver every time.
  14 --
  15 lookup_mxs :: Domain -> IO [Domain]
  16 lookup_mxs domain = do
  17   default_rs <- makeResolvSeed defaultResolvConf
  18   withResolver default_rs $ \resolver -> do
  19     mxs <- lookupMX resolver domain
  20     return $ case mxs of
  21                Left  _     -> []
  22                Right pairs -> map fst pairs