diff --git a/config/settings.yml b/config/settings.yml
index aea998f4b..5a120e906 100644
--- a/config/settings.yml
+++ b/config/settings.yml
@@ -35,7 +35,7 @@ bearer-expiration: 604800
 bearer-encoding: HS256
 maximum-content-length: "_env:MAX_UPLOAD_SIZE:134217728"
 session-files-expire: 3600
-prune-unreferenced-files: 600
+prune-unreferenced-files: 28800
 keep-unreferenced-files: 86400
 health-check-interval:
   matching-cluster-config: "_env:HEALTHCHECK_INTERVAL_MATCHING_CLUSTER_CONFIG:600"
diff --git a/src/Database/Esqueleto/Utils.hs b/src/Database/Esqueleto/Utils.hs
index 36c33d573..474fe9fe9 100644
--- a/src/Database/Esqueleto/Utils.hs
+++ b/src/Database/Esqueleto/Utils.hs
@@ -298,6 +298,8 @@ instance (PersistEntity val, PersistField typ) => SqlProject val typ (Maybe (E.E
   sqlProject = (E.?.)
   unSqlProject _ _ = Just
 
+infixl 8 ->.
+
 (->.) :: E.SqlExpr (E.Value a) -> Text -> E.SqlExpr (E.Value b)
 (->.) expr t = E.unsafeSqlBinOp "->" expr $ E.val t
 
diff --git a/src/Handler/Admin/Test.hs b/src/Handler/Admin/Test.hs
index c31fd691b..645152b0e 100644
--- a/src/Handler/Admin/Test.hs
+++ b/src/Handler/Admin/Test.hs
@@ -86,11 +86,9 @@ postAdminTestR = do
 
   ((emailResult, emailWidget), emailEnctype) <- runFormPost . identifyForm ("email" :: Text) $ renderAForm FormStandard emailTestForm
   formResultModal emailResult AdminTestR $ \(email, ls) -> do
-    jId <- mapWriterT runDB $ do
-      jId <- queueJob $ JobSendTestEmail email ls
-      tell . pure $ Message Success [shamlet|Email-test gestartet (Job ##{tshow (fromSqlKey jId)})|] (Just IconEmail)
-      return jId
-    runReaderT (writeJobCtl $ JobCtlPerform jId) =<< getYesod
+    mapWriterT runDBJobs $ do
+      lift . queueDBJob $ JobSendTestEmail email ls
+      tell . pure $ Message Success [shamlet|Email-test gestartet|] (Just IconEmail)
     addMessage Warning [shamlet|Inkorrekt ausgegebener Alert|] -- For testing alert handling when short circuiting; for proper (not fallback-solution) handling always use `tell` within `formResultModal`
 
   let emailWidget' = wrapForm emailWidget def
diff --git a/src/Handler/Utils/Exam.hs b/src/Handler/Utils/Exam.hs
index 8ba5f5584..cc8405762 100644
--- a/src/Handler/Utils/Exam.hs
+++ b/src/Handler/Utils/Exam.hs
@@ -1,4 +1,4 @@
-{-# OPTIONS_GHC -fno-warn-deprecations -fno-warn-incomplete-uni-patterns #-}
+{-# OPTIONS_GHC -fno-warn-incomplete-uni-patterns #-}
 
 module Handler.Utils.Exam
   ( fetchExamAux
@@ -519,7 +519,7 @@ examAutoOccurrence (hash -> seed) rule ExamAutoOccurrenceConfig{..} occurrences
                    )
     postprocess result = (resultAscList, resultUsers)
       where
-        resultAscList = pad . Map.fromListWith Set.union . accRes (pure <$> Set.lookupMin rangeAlphabet) $ (\r -> traceShow (over (traverse . _2 . traverse . traverse) CI.original r) r) result
+        resultAscList = pad . Map.fromListWith Set.union $ accRes (pure <$> Set.lookupMin rangeAlphabet) result
           where
             accRes _ [] = []
             accRes prevEnd ((occA, nsA) : (occB, nsB) : xs)
diff --git a/src/Jobs/Queue.hs b/src/Jobs/Queue.hs
index 045649ed1..18c85be59 100644
--- a/src/Jobs/Queue.hs
+++ b/src/Jobs/Queue.hs
@@ -80,22 +80,28 @@ writeJobCtlBlock :: (MonadThrow m, MonadIO m, MonadReader UniWorX m) => JobCtl -
 -- | Pass an instruction to the `Job`-Workers and block until it was acted upon
 writeJobCtlBlock = writeJobCtlBlock' writeJobCtl
 
-queueJobUnsafe :: Bool -> Job -> YesodDB UniWorX QueuedJobId
+queueJobUnsafe :: Bool -> Job -> YesodDB UniWorX (Maybe QueuedJobId)
 queueJobUnsafe queuedJobWriteLastExec job = do
   $logInfoS "queueJob" $ tshow job
-  queuedJobCreationTime <- liftIO getCurrentTime
-  queuedJobCreationInstance <- getsYesod appInstanceID
-  insert QueuedJob
-    { queuedJobContent = toJSON job
-    , queuedJobLockInstance = Nothing
-    , queuedJobLockTime = Nothing
-    , ..
-    }
-  -- We should not immediately notify a worker; instead wait for the transaction to finish first
-  -- writeJobCtl $ JobCtlPerform jId -- FIXME: Should do fancy load balancing across instances (or something)
-  -- return jId
+  
+  doQueue <- fmap not . and2M (return $ jobNoQueueSame job) $ exists [ QueuedJobContent ==. toJSON job ]
+  
+  if
+    | doQueue -> Just <$> do
+        queuedJobCreationTime <- liftIO getCurrentTime
+        queuedJobCreationInstance <- getsYesod appInstanceID
+        insert QueuedJob
+          { queuedJobContent = toJSON job
+          , queuedJobLockInstance = Nothing
+          , queuedJobLockTime = Nothing
+          , ..
+          }
+        -- We should not immediately notify a worker; instead wait for the transaction to finish first
+        -- writeJobCtl $ JobCtlPerform jId -- FIXME: Should do fancy load balancing across instances (or something)
+        -- return jId
+    | otherwise -> return Nothing
 
-queueJob :: (MonadHandler m, HandlerSite m ~ UniWorX) => Job -> m QueuedJobId
+queueJob :: (MonadHandler m, HandlerSite m ~ UniWorX) => Job -> m (Maybe QueuedJobId)
 -- ^ Queue a job for later execution
 --
 -- Makes no guarantees as to when it will be executed (`queueJob'`) and does not interact with any running database transactions (`runDBJobs`)
@@ -105,15 +111,15 @@ queueJob' :: (MonadThrow m, MonadHandler m, HandlerSite m ~ UniWorX) => Job -> m
 -- ^ `queueJob` followed by `writeJobCtl` `JobCtlPerform` to ensure, that it is executed asap
 queueJob' job = do
   app <- getYesod
-  queueJob job >>= flip runReaderT app . writeJobCtl . JobCtlPerform
+  queueJob job >>= maybe (return ()) (flip runReaderT app . writeJobCtl . JobCtlPerform)
 
 -- | Slightly modified Version of `DB` for `runDBJobs`
 type JobDB = YesodJobDB UniWorX
 
 queueDBJob, queueDBJobCron :: Job -> YesodJobDB UniWorX ()
 -- | Queue a job as part of a database transaction and execute it after the transaction succeeds
-queueDBJob job = mapReaderT lift (queueJobUnsafe False job) >>= tell . Set.singleton
-queueDBJobCron job = mapReaderT lift (queueJobUnsafe True job) >>= tell . Set.singleton
+queueDBJob job = mapReaderT lift (queueJobUnsafe False job) >>= tell . maybe Set.empty Set.singleton
+queueDBJobCron job = mapReaderT lift (queueJobUnsafe True job) >>= tell . maybe Set.empty Set.singleton
 
 sinkDBJobs :: ConduitT Job Void (YesodJobDB UniWorX) ()
 -- | Queue many jobs as part of a database transaction and execute them after the transaction passes
diff --git a/src/Jobs/Types.hs b/src/Jobs/Types.hs
index a7b56be8d..11fe8b12e 100644
--- a/src/Jobs/Types.hs
+++ b/src/Jobs/Types.hs
@@ -17,6 +17,7 @@ module Jobs.Types
   , showWorkerId, newWorkerId
   , JobQueue, jqInsert, jqDequeue
   , JobPriority(..), prioritiseJob
+  , jobNoQueueSame
   , module Cron
   ) where
 
@@ -235,6 +236,19 @@ prioritiseJob (JobCtlGenerateHealthReport _)  = JobPrioRealtime
 prioritiseJob  JobCtlDetermineCrontab         = JobPrioRealtime
 prioritiseJob  _                              = JobPrioBatch
 
+jobNoQueueSame :: Job -> Bool
+jobNoQueueSame = \case
+  JobSendPasswordReset{}       -> True
+  JobTruncateTransactionLog{}  -> True
+  JobPruneInvitations{}        -> True
+  JobDeleteTransactionLogIPs{} -> True
+  JobSynchroniseLdapUser{}     -> True
+  JobChangeUserDisplayEmail{}  -> True
+  JobPruneSessionFiles{}       -> True
+  JobPruneUnreferencedFiles{}  -> True
+  JobInjectFiles{}             -> True
+  _                            -> False
+
 
 newtype JobQueue = JobQueue { getJobQueue :: MaxPQueue JobPriority JobCtl }
   deriving (Eq, Ord, Read, Show)