diff --git a/cabal.project b/cabal.project
index 3595f999e3..859f5ac1ac 100644
--- a/cabal.project
+++ b/cabal.project
@@ -12,7 +12,7 @@ constraints: zip +disable-bzip2 +disable-zstd
 source-repository-package
     type: git
     location: https://github.com/simplex-chat/simplexmq.git
-    tag: e3f5d244c1a435593e33adc023bf1f920f379f8d
+    tag: e7a73a4c89ed02e248e2d77e267037c9d4433820
 
 source-repository-package
     type: git
diff --git a/scripts/nix/sha256map.nix b/scripts/nix/sha256map.nix
index a1f698fb4e..b4c90d8980 100644
--- a/scripts/nix/sha256map.nix
+++ b/scripts/nix/sha256map.nix
@@ -1,5 +1,5 @@
 {
-  "https://github.com/simplex-chat/simplexmq.git"."e3f5d244c1a435593e33adc023bf1f920f379f8d" = "1klin78kgvgzdvf64nahn3280m7hw5f8wzrca43cmyajm2qp3wfs";
+  "https://github.com/simplex-chat/simplexmq.git"."e7a73a4c89ed02e248e2d77e267037c9d4433820" = "1zrsvnx8qnkvlxhkikl97bmi5nyian8wq20pn330159cviihfxl1";
   "https://github.com/simplex-chat/hs-socks.git"."a30cc7a79a08d8108316094f8f2f82a0c5e1ac51" = "0yasvnr7g91k76mjkamvzab2kvlb1g5pspjyjn2fr6v83swjhj38";
   "https://github.com/simplex-chat/direct-sqlcipher.git"."f814ee68b16a9447fbb467ccc8f29bdd3546bfd9" = "1ql13f4kfwkbaq7nygkxgw84213i0zm7c1a8hwvramayxl38dq5d";
   "https://github.com/simplex-chat/sqlcipher-simple.git"."a46bd361a19376c5211f1058908fc0ae6bf42446" = "1z0r78d8f0812kxbgsm735qf6xx8lvaz27k1a0b4a2m0sshpd5gl";
diff --git a/src/Simplex/Chat.hs b/src/Simplex/Chat.hs
index 743cef932c..1165c7ccff 100644
--- a/src/Simplex/Chat.hs
+++ b/src/Simplex/Chat.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE BangPatterns #-}
 {-# LANGUAGE DataKinds #-}
 {-# LANGUAGE DuplicateRecordFields #-}
 {-# LANGUAGE FlexibleContexts #-}
@@ -1701,7 +1702,7 @@ processChatCommand' vr = \case
           sndMsgs <- lift $ createSndMessages idsEvts
           let msgReqs_ :: NonEmpty (Either ChatError MsgReq) = L.zipWith (fmap . ctMsgReq) ctConns sndMsgs
           (errs, ctSndMsgs :: [(Contact, SndMessage)]) <-
-            lift $ partitionEithers . L.toList . zipWith3' combineResults ctConns sndMsgs <$> deliverMessagesB msgReqs_
+            partitionEithers . L.toList . zipWith3' combineResults ctConns sndMsgs <$> deliverMessagesB msgReqs_
           timestamp <- liftIO getCurrentTime
           lift . void $ withStoreBatch' $ \db -> map (createCI db user timestamp) ctSndMsgs
           pure CRBroadcastSent {user, msgContent = mc, successes = length ctSndMsgs, failures = length errs, timestamp}
@@ -2397,7 +2398,7 @@ processChatCommand' vr = \case
               Just changedCts -> do
                 let idsEvts = L.map ctSndEvent changedCts
                 msgReqs_ <- lift $ L.zipWith ctMsgReq changedCts <$> createSndMessages idsEvts
-                (errs, cts) <- lift $ partitionEithers . L.toList . L.zipWith (second . const) changedCts <$> deliverMessagesB msgReqs_
+                (errs, cts) <- partitionEithers . L.toList . L.zipWith (second . const) changedCts <$> deliverMessagesB msgReqs_
                 unless (null errs) $ toView $ CRChatErrors (Just user) errs
                 let changedCts' = filter (\ChangedProfileContact {ct, ct'} -> directOrUsed ct' && mergedPreferences ct' /= mergedPreferences ct) cts
                 lift $ createContactsSndFeatureItems user' changedCts'
@@ -6561,21 +6562,21 @@ deliverMessage conn cmEventTag msgBody msgId = do
 
 deliverMessage' :: Connection -> MsgFlags -> MsgBody -> MessageId -> CM (Int64, PQEncryption)
 deliverMessage' conn msgFlags msgBody msgId =
-  lift (deliverMessages ((conn, msgFlags, msgBody, msgId) :| [])) >>= \case
+  deliverMessages ((conn, msgFlags, msgBody, msgId) :| []) >>= \case
     r :| [] -> liftEither r
     rs -> throwChatError $ CEInternalError $ "deliverMessage: expected 1 result, got " <> show (length rs)
 
 type MsgReq = (Connection, MsgFlags, MsgBody, MessageId)
 
-deliverMessages :: NonEmpty MsgReq -> CM' (NonEmpty (Either ChatError (Int64, PQEncryption)))
+deliverMessages :: NonEmpty MsgReq -> CM (NonEmpty (Either ChatError (Int64, PQEncryption)))
 deliverMessages msgs = deliverMessagesB $ L.map Right msgs
 
-deliverMessagesB :: NonEmpty (Either ChatError MsgReq) -> CM' (NonEmpty (Either ChatError (Int64, PQEncryption)))
+deliverMessagesB :: NonEmpty (Either ChatError MsgReq) -> CM (NonEmpty (Either ChatError (Int64, PQEncryption)))
 deliverMessagesB msgReqs = do
   msgReqs' <- liftIO compressBodies
-  sent <- L.zipWith prepareBatch msgReqs' <$> withAgent' (`sendMessagesB` L.map toAgent msgReqs')
-  void $ withStoreBatch' $ \db -> map (updatePQSndEnabled db) (rights . L.toList $ sent)
-  withStoreBatch $ \db -> L.map (bindRight $ createDelivery db) sent
+  sent <- L.zipWith prepareBatch msgReqs' <$> withAgent (`sendMessagesB` L.map toAgent msgReqs')
+  lift . void $ withStoreBatch' $ \db -> map (updatePQSndEnabled db) (rights . L.toList $ sent)
+  lift . withStoreBatch $ \db -> L.map (bindRight $ createDelivery db) sent
   where
     compressBodies =
       forME msgReqs $ \mr@(conn@Connection {pqSupport, connChatVersion = v}, msgFlags, msgBody, msgId) ->
@@ -6634,10 +6635,11 @@ sendGroupMessage' user GroupInfo {groupId} members chatMsgEvent = do
   msg@SndMessage {msgId, msgBody} <- createSndMessage chatMsgEvent (GroupId groupId)
   recipientMembers <- liftIO $ shuffleMembers (filter memberCurrent members)
   let msgFlags = MsgFlags {notification = hasNotification $ toCMEventTag chatMsgEvent}
-      (toSend, pending) = foldr addMember ([], []) recipientMembers
+      (toSend, pending, _, dups) = foldr addMember ([], [], S.empty, 0 :: Int) recipientMembers
       -- TODO PQ either somehow ensure that group members connections cannot have pqSupport/pqEncryption or pass Off's here
       msgReqs = map (\(_, conn) -> (conn, msgFlags, msgBody, msgId)) toSend
-  delivered <- maybe (pure []) (fmap L.toList . lift . deliverMessages) $ L.nonEmpty msgReqs
+  when (dups /= 0) $ logError $ "sendGroupMessage: " <> tshow dups <> " duplicate members"
+  delivered <- maybe (pure []) (fmap L.toList . deliverMessages) $ L.nonEmpty msgReqs
   let errors = lefts delivered
   unless (null errors) $ toView $ CRChatErrors (Just user) errors
   stored <- lift . withStoreBatch' $ \db -> map (\m -> createPendingGroupMessage db (groupMemberId' m) msgId Nothing) pending
@@ -6650,10 +6652,16 @@ sendGroupMessage' user GroupInfo {groupId} members chatMsgEvent = do
       liftM2 (<>) (shuffle adminMs) (shuffle otherMs)
       where
         isAdmin GroupMember {memberRole} = memberRole >= GRAdmin
-    addMember m (toSend, pending) = case memberSendAction chatMsgEvent members m of
-      Just (MSASend conn) -> ((m, conn) : toSend, pending)
-      Just MSAPending -> (toSend, m : pending)
-      Nothing -> (toSend, pending)
+    addMember m acc@(toSend, pending, !mIds, !dups) = case memberSendAction chatMsgEvent members m of
+      Just a
+        | mId `S.member` mIds -> (toSend, pending, mIds, dups + 1)
+        | otherwise -> case a of
+            MSASend conn -> ((m, conn) : toSend, pending, mIds', dups)
+            MSAPending -> (toSend, m : pending, mIds', dups)
+      Nothing -> acc
+      where
+        mId = groupMemberId' m
+        mIds' = S.insert mId mIds
     filterSent :: [Either ChatError a] -> [mem] -> (mem -> GroupMember) -> [GroupMember]
     filterSent rs ms mem = [mem m | (Right _, m) <- zip rs ms]
 
diff --git a/src/Simplex/Chat/Archive.hs b/src/Simplex/Chat/Archive.hs
index 8550c03438..01897de791 100644
--- a/src/Simplex/Chat/Archive.hs
+++ b/src/Simplex/Chat/Archive.hs
@@ -26,6 +26,7 @@ import Data.Text (Text)
 import qualified Data.Text as T
 import qualified Database.SQLite3 as SQL
 import Simplex.Chat.Controller
+import Simplex.Chat.Util ()
 import Simplex.Messaging.Agent.Client (agentClientStore)
 import Simplex.Messaging.Agent.Store.SQLite (SQLiteStore (..), closeSQLiteStore, keyString, sqlString, storeKey)
 import Simplex.Messaging.Util
diff --git a/src/Simplex/Chat/Util.hs b/src/Simplex/Chat/Util.hs
index 2b2bd599ae..3f7d19fd6d 100644
--- a/src/Simplex/Chat/Util.hs
+++ b/src/Simplex/Chat/Util.hs
@@ -1,10 +1,18 @@
+{-# LANGUAGE FlexibleInstances #-}
+{-# LANGUAGE InstanceSigs #-}
+{-# LANGUAGE RankNTypes #-}
 {-# LANGUAGE TupleSections #-}
+{-# OPTIONS_GHC -Wno-orphans #-}
 
 module Simplex.Chat.Util (week, encryptFile, chunkSize, liftIOEither, shuffle) where
 
+import Control.Exception (Exception)
 import Control.Monad
 import Control.Monad.Except
 import Control.Monad.IO.Class
+import Control.Monad.IO.Unlift (MonadUnliftIO (..))
+import Control.Monad.Reader
+import Data.Bifunctor (first)
 import qualified Data.ByteString.Lazy as LB
 import Data.List (sortBy)
 import Data.Ord (comparing)
@@ -13,6 +21,7 @@ import Data.Word (Word16)
 import Simplex.Messaging.Crypto.File (CryptoFile (..), CryptoFileArgs (..))
 import qualified Simplex.Messaging.Crypto.File as CF
 import System.Random (randomRIO)
+import qualified UnliftIO.Exception as E
 import UnliftIO.IO (IOMode (..), withFile)
 
 week :: NominalDiffTime
@@ -46,3 +55,24 @@ shuffle xs = map snd . sortBy (comparing fst) <$> mapM (\x -> (,x) <$> random) x
 liftIOEither :: (MonadIO m, MonadError e m) => IO (Either e a) -> m a
 liftIOEither a = liftIO a >>= liftEither
 {-# INLINE liftIOEither #-}
+
+newtype InternalException e = InternalException {unInternalException :: e}
+  deriving (Eq, Show)
+
+instance Exception e => Exception (InternalException e)
+
+instance Exception e => MonadUnliftIO (ExceptT e IO) where
+  {-# INLINE withRunInIO #-}
+  withRunInIO :: ((forall a. ExceptT e IO a -> IO a) -> IO b) -> ExceptT e IO b
+  withRunInIO inner =
+    ExceptT . fmap (first unInternalException) . E.try $
+      withRunInIO $ \run ->
+        inner $ run . (either (E.throwIO . InternalException) pure <=< runExceptT)
+
+instance Exception e => MonadUnliftIO (ExceptT e (ReaderT r IO)) where
+  {-# INLINE withRunInIO #-}
+  withRunInIO :: ((forall a. ExceptT e (ReaderT r IO) a -> IO a) -> IO b) -> ExceptT e (ReaderT r IO) b
+  withRunInIO inner =
+    withExceptT unInternalException . ExceptT . E.try $
+      withRunInIO $ \run ->
+        inner $ run . (either (E.throwIO . InternalException) pure <=< runExceptT)