diff --git a/core/base/libs/podop/podop/dovecot.py b/core/base/libs/podop/podop/dovecot.py
index 18956dd4..6dc25af5 100644
--- a/core/base/libs/podop/podop/dovecot.py
+++ b/core/base/libs/podop/podop/dovecot.py
@@ -40,6 +40,7 @@ class DictProtocol(asyncio.Protocol):
     def connection_made(self, transport):
         logging.info('Connect {}'.format(transport.get_extra_info('peername')))
         self.transport = transport
+        self.transport_lock = asyncio.Lock()
 
     def data_received(self, data):
         logging.debug("Received {}".format(data))
@@ -94,9 +95,9 @@ class DictProtocol(asyncio.Protocol):
             else:
                 response = json.dumps(result).encode("ascii")
             logging.debug("Replying {}".format(key))
-            return self.reply(b"O", (key_type+'/'+key).encode("utf8"), response, end=True) if is_iter else self.reply(b"O", response)
+            return await (self.reply(b"O", (key_type+'/'+key).encode("utf8"), response, end=True) if is_iter else self.reply(b"O", response))
         except KeyError:
-            return self.reply(b"N")
+            return await self.reply(b"N")
 
     async def process_iterate(self, flags, max_rows, path, user=None):
         """ Process an iterate command
@@ -107,18 +108,24 @@ class DictProtocol(asyncio.Protocol):
         max_rows = int(max_rows.decode("utf-8"))
         flags = int(flags.decode("utf-8"))
         if flags != 0: # not implemented
-            return self.reply(b"F")
+            return await self.reply(b"F")
+        rows = []
         try:
             result = await self.dict.iter(key)
             logging.debug("Found {} entries: {}".format(len(result), result))
             returned_results = 0
             for k in result:
                 if max_rows == 0 or returned_results < max_rows:
-                    await self.process_lookup((path.decode("utf8")+k).encode("utf8"), user, is_iter=True)
+                    rows.append(self.process_lookup((path.decode("utf8")+k).encode("utf8"), user, is_iter=True))
                     returned_results += 1
-            return self.reply(b"\n") # ITER_FINISHED
+            await asyncio.gather(*rows)
+            return await self.reply(b"\n") # ITER_FINISHED
         except KeyError:
-            return self.reply(b"F")
+            return await self.reply(b"F")
+        except Exception as e:
+            logging.error(f"Got {e}, cancelling remaining tasks")
+            for task in rows:
+                task.cancel()
 
     def process_begin(self, transaction_id, user=None):
         """ Process a dict begin message
@@ -147,14 +154,15 @@ class DictProtocol(asyncio.Protocol):
         # Remove stored transaction
         del self.transactions[transaction_id]
         del self.transactions_user[transaction_id]
-        return self.reply(b"O", transaction_id)
+        return await self.reply(b"O", transaction_id)
 
-    def reply(self, command, *args, end=True):
+    async def reply(self, command, *args, end=True):
         logging.debug("Replying {} with {}".format(command, args))
-        self.transport.write(command)
-        self.transport.write(b"\t".join(map(tabescape, args)))
-        if end:
-            self.transport.write(b"\n")
+        async with self.transport_lock:
+            self.transport.write(command)
+            self.transport.write(b"\t".join(map(tabescape, args)))
+            if end:
+                self.transport.write(b"\n")
 
     @classmethod
     def factory(cls, table_map):