--- test-mailman-2.1/Mailman/Handlers/SMTPDirect.py	2010-07-03 14:12:22.000000000 -0700
+++ test-mailman/Mailman/Handlers/SMTPDirect.py	2011-02-04 19:29:49.234375000 -0800
@@ -52,6 +52,37 @@
     True = 1
     False = 0
 
+# Throttling settings.  Do not send to more than THROTTLE_LIMIT recipients
+# within THROTTLE_TIME seconds.  Set THROTTLE_LIMIT to 0 to not throttle.
+THROTTLE_TIME = 60
+THROTTLE_LIMIT = 2000
+THROTTLE_DATA = []
+
+# check throttling.  Doesn't return until total recipients in THROTTLE_TIME
+# <= THROTTLE_LIMIT.
+# 
+def check_throttle(count):
+    global THROTTLE_DATA
+    if THROTTLE_LIMIT <= 0:
+        return
+    if count <= 0 or count > THROTTLE_LIMIT:
+        syslog('error', 'check_throttle: count=%d; THROTTLE_LIMIT=%d',
+               count, THROTTLE_LIMIT)
+        return
+    now = time.time()
+    total = 0
+    THROTTLE_DATA = [(num, tim) for (num, tim) in THROTTLE_DATA
+                     if tim > now - THROTTLE_TIME]
+    for num, tim in THROTTLE_DATA:
+        total += num
+    total += count
+    if total > THROTTLE_LIMIT:
+        time.sleep(THROTTLE_TIME - now + THROTTLE_DATA[0][1])
+        check_throttle(count)
+    else:
+        THROTTLE_DATA.append((count, now))
+        return
+
 
 
 # Manage a connection to the SMTP server
@@ -118,10 +149,14 @@
         chunks = [[recip] for recip in recips]
         msgdata['personalize'] = 1
         deliveryfunc = verpdeliver
-    elif mm_cfg.SMTP_MAX_RCPTS <= 0:
+    elif mm_cfg.SMTP_MAX_RCPTS <= 0 and (THROTTLE_LIMIT <=0 or
+                                         THROTTLE_LIMIT >= len(recips)):
         chunks = [recips]
     else:
-        chunks = chunkify(recips, mm_cfg.SMTP_MAX_RCPTS)
+        if THROTTLE_LIMIT <= 0 or THROTTLE_LIMIT > mm_cfg.SMTP_MAX_RCPTS:
+            chunks = chunkify(recips, mm_cfg.SMTP_MAX_RCPTS)
+        else:
+            chunks = chunkify(recips, THROTTLE_LIMIT)
     # See if this is an unshunted message for which some were undelivered
     if msgdata.has_key('undelivered'):
         chunks = msgdata['undelivered']
@@ -384,6 +419,8 @@
     msgid = msg['message-id']
     try:
         # Send the message
+        # but wait if necessary for throttling
+        check_throttle(len(recips))
         refused = conn.sendmail(envsender, recips, msgtext)
     except smtplib.SMTPRecipientsRefused, e:
         syslog('smtp-failure', 'All recipients refused: %s, msgid: %s',