diff --git a/scopes/core/actor.py b/scopes/core/actor.py
index 4863b0a..b2787f6 100644
--- a/scopes/core/actor.py
+++ b/scopes/core/actor.py
@@ -4,9 +4,11 @@ import asyncio
 from collections.abc import Awaitable, Callable
 from typing import Any, Optional
 
-from scopes.util import keywords as k
+from scopes.util import keywords as k, Symbol
+k('full quit')
 
 type Behavior = Callable[[Any], Awaitable[Behavior | None]]
+type Mailbox = asyncio.Queue
 
 async def loop(q: asyncio.Queue, bhv: Behavior) -> None:
     while True:
@@ -14,12 +16,20 @@ async def loop(q: asyncio.Queue, bhv: Behavior) -> None:
         if msg is k.quit: 
             break
         bhv = await bhv(msg) or bhv
+        q.task_done()
 
-def create(bhv: Behavior, group: Optional[asyncio.TaskGroup] = None) -> asyncio.Queue:
-    q: asyncio.Queue = asyncio.Queue()
+def create(bhv: Behavior, maxsize: int = 0, 
+           group: Optional[asyncio.TaskGroup] = None) -> asyncio.Queue:
+    q: asyncio.Queue = asyncio.Queue(maxsize)
     if group is None:
         asyncio.create_task(loop(q, bhv))
     else:
         group.create_task(loop(q, bhv))
     return q
 
+async def try_send(rcvr: Mailbox, msg: Any) -> Symbol | None:
+    if rcvr.full():
+        return k.full
+    await rcvr.put(msg)
+    return None
+