diff --git a/bots/zephyr_mirror.py b/bots/zephyr_mirror.py
index ce73e4b..3da5eb9 100755
--- a/bots/zephyr_mirror.py
+++ b/bots/zephyr_mirror.py
@@ -391,7 +391,16 @@ def forward_to_zephyr(message):
     p.communicate(input=wrapped_content)
 
 def maybe_forward_to_zephyr(message):
-    if message["sender_email"] == options.user + "@mit.edu":
+    if (message["sender_email"] == options.user + "@mit.edu"):
+        if not ((message["type"] == "stream") or
+                (message["type"] == "personal" and
+                 message["display_recipient"]["email"].lower().endswith("mit.edu")) or
+                (message["type"] == "huddle" and
+                 False not in [u["email"].lower().endswith("mit.edu") for u in
+                               message["display_recipient"]])):
+            # Don't try forward personals/huddles with non-MIT users
+            # to MIT Zephyr.
+            return
         timestamp_now = datetime.datetime.now().strftime("%s")
         if float(message["timestamp"]) < float(timestamp_now) - 15:
             print "%s humbug=>zephyr: Alert!  Out of order message: %s < %s" % \