diff --git a/config/keter_testworx.yml b/config/keter_testworx.yml
index 4f1d648db..6ec58b7ba 100644
--- a/config/keter_testworx.yml
+++ b/config/keter_testworx.yml
@@ -49,6 +49,8 @@ stanzas:
       - SMTPPASS
       - SMTPTIMEOUT
       - SMTPLIMIT
+      - MAILSUPPORT
+      - MAILSUPPORT_NAME
       - INSTANCE_ID
       - MEMCACHEDHOST
       - MEMCACHEDPORT
diff --git a/config/keter_uni2work.yml b/config/keter_uni2work.yml
index 15f9eee7e..f3fa11860 100644
--- a/config/keter_uni2work.yml
+++ b/config/keter_uni2work.yml
@@ -48,6 +48,8 @@ stanzas:
       - SMTPPASS
       - SMTPTIMEOUT
       - SMTPLIMIT
+      - MAILSUPPORT
+      - MAILSUPPORT_NAME
       - INSTANCE_ID
       - MEMCACHEDHOST
       - MEMCACHEDPORT
diff --git a/config/settings.yml b/config/settings.yml
index 0a8252dae..e681e8e27 100644
--- a/config/settings.yml
+++ b/config/settings.yml
@@ -16,8 +16,8 @@ mail-verp:
   separator:    "+"
   at-replacement: "="
 mail-support:
-  name:         null
-  email:        "uni2work@ifi.lmu.de"
+  name:         "_env:MAILSUPPORT_NAME:"
+  email:        "_env:MAILSUPPORT:uni2work@ifi.lmu.de"
 
 job-workers:        "_env:JOB_WORKERS:10"
 job-flush-interval: "_env:JOB_FLUSH:30"
diff --git a/src/Network/Mail/Mime/Instances.hs b/src/Network/Mail/Mime/Instances.hs
index b7d1b26d6..18c22e67a 100644
--- a/src/Network/Mail/Mime/Instances.hs
+++ b/src/Network/Mail/Mime/Instances.hs
@@ -12,6 +12,8 @@ import Data.Aeson
 import Data.Aeson.TH
 
 import Utils.PathPiece
+
+import Utils (assertM)
   
 
 deriving instance Read Address
@@ -20,6 +22,12 @@ deriving instance Generic Address
 
 instance Hashable Address
 
-deriveJSON defaultOptions
+deriveToJSON defaultOptions
   { fieldLabelModifier = intercalate "-" . map toLower . drop 1 . splitCamel
   } ''Address
+
+instance FromJSON Address where
+  parseJSON = withObject "Address" $ \obj -> do
+    addressName <- assertM (not . null) <$> (obj .:? "name")
+    addressEmail <- obj .: "email"
+    return Address{..}
diff --git a/src/Settings.hs b/src/Settings.hs
index f511e579b..b6d7c3397 100644
--- a/src/Settings.hs
+++ b/src/Settings.hs
@@ -59,11 +59,15 @@ import qualified Database.Memcached.Binary.Types as Memcached
 import Model
 import Settings.Cluster
 
+import Control.Monad.Trans.Maybe (MaybeT(..))
+
+import qualified System.FilePath as FilePath
+
 -- | Runtime settings to configure this application. These settings can be
 -- loaded from various sources: defaults, environment variables, config files,
 -- theoretically even a database.
 data AppSettings = AppSettings
-    { appStaticDir              :: String
+    { appStaticDir              :: FilePath
     -- ^ Directory from which to serve static files.
     , appDatabaseConf           :: PostgresConf
     -- ^ Configuration settings for accessing the database.
@@ -360,7 +364,13 @@ instance FromJSON AppSettings where
         appUserDefaults           <- o .:  "user-defaults"
         appAuthPWHash             <- o .:  "auth-pw-hash"
 
-        appInitialInstanceID      <- (o .:? "instance-id") >>= maybe (return Nothing) (\v -> Just <$> ((Right <$> parseJSON v) <|> (Left <$> parseJSON v)))
+        appInitialInstanceID      <- runMaybeT $ do
+          val <- MaybeT (o .:? "instance-id")
+          val' <- lift $ (Right <$> parseJSON val) <|> (Left <$> parseJSON val)
+          case val' of
+            Left fp -> guard $ FilePath.isValid fp
+            _       -> return ()
+          return val'
 
         return AppSettings {..}
 
diff --git a/stack.nix b/stack.nix
index 971fbc175..7a8a0dcbf 100644
--- a/stack.nix
+++ b/stack.nix
@@ -7,7 +7,7 @@ in haskell.lib.buildStackProject {
   inherit ghc;
   name = "stackenv";
   buildInputs = (with pkgs;
-    [ postgresql zlib openldap cyrus_sasl.dev libsodium
+    [ postgresql zlib libsodium
     ]) ++ (with haskellPackages;
     [ yesod-bin
     ]);