[Mailman-Developers] [ mailman-Bugs-558633 ] Blocked queue after fight with Majordomo

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Bugs item #558633, was opened at 2002-05-21 08:01
You can respond by visiting: 
http://sourceforge.net/tracker/?func=detail&atid=100103&aid=558633&group_id=103

Category: mail delivery
Group: 2.0.x
Status: Open
Resolution: None
Priority: 5
Submitted By: Nigel Metheringham (nigel)
Assigned to: Nobody/Anonymous (nobody)
Summary: Blocked queue after fight with Majordomo

Initial Comment:
On Mailman 2.0.8 (was honestly going to upgrade today!).

It appears that a couple of messages were boucing
between the mailman request addresses and a Majordomo
server,
with more error transcript being added to the message
on each bounce.   This then appeared to completely 
block the qrunner.   Removing the 2 huge messages
from the qfiles directory fixed it.


Broken message qfiles attached.


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>Comment By: Barry Warsaw (bwarsaw)
Date: 2002-05-21 22:38

Message:
Logged In: YES 
user_id=12800

Norbert Bollow gives this very good idea:

Rate limiting can do a lot to prevent things from getting
out of hand.  For example, respond at most ten times to
essentially the same request from the same email address.

On any given day, when Mailman gets the tenth message from the
same email address without valid commands, it could reply "This
is the tenth message of this type today from you.  It order to
avoid problems like mail loops between email robots, any further
messages of this type will be ignored today.  Please try again
tomorrow."  And then any further messages from that address with
no valid commands will be just discarded.

Similarly, Mailman would reply only to ten subscription requests
for the same list from the same user on any given day.  And only
to ten unsubscription requests for the same list from the same
user on any given day.  And only to ten requests to change the
subscription options in the same way.  Etc.

Since most loops (with the exception of some bounce loops)
iterate more quickly than ten times per day, this will kill most
loops between robots before they create serious problems.


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Comment By: Barry Warsaw (bwarsaw)
Date: 2002-05-21 16:47

Message:
Logged In: YES 
user_id=12800

Heh, I think this is a general problem when you get two
email robots talking to each other!  In MM2.1cvs the robot
will refuse to respond to a message marked Precedence:
bulk|junk|list -- but it looks like that wouldn't have even
helped in this case (since the Majordomo server isnt'
setting that header ;/ )

The only other solution I can think of is to add a config
variable which is a blacklist of known addresses (regexps)
that Mailman should not respond too.  You'd still get into
the robot infloop the first time, but at least you'd have a
hope of avoiding subsequent replybot storms for the same
address.


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Comment By: Nigel Metheringham (nigel)
Date: 2002-05-21 08:03

Message:
Logged In: YES 
user_id=31288

and other file

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