[Mailman-Users] Looping problem

[Arshad Mahmood]

Hi,

My domain is "abc.org". We have two mail servers in two centers. And the
email address format of users at the two centers is

user at center1.abc.org
user at center2.abc.org

We are using Mailman at the both centers.

Now consider the mailing list xyz.

The mailing list "xyz" is present at the both centers.

Now the problem is that we want that if a user at center1 which is
subscribed at "xyz" list sends a mail to list "xyz at center1.abc.org" then
this mail should go to to all users that are subscribed to list xyz at
center2 that is that sholud also go to "xyz at center1.abc.org". And for
operation list xyz at center2 "xyz at center1.abc.org" should be subscribed
to xyz list at center1.

Similarly if a user at center2 which is subscribed at "xyz" list sends a 
mail to list "xyz at center2.abc.org" then this mail should go to to all 
users that are subscribed to list xyz at center1 that is that sholud also
go to "xyz at center1.abc.org". And for operation list xyz at center1
"xyz at center1.abc.org" should be subscribed to xyz list at center2. 

Now the condition above described is a loop. As the list at center1 is
subscribed center2 and list at center2 is subscribed at center1, this is
loop. Mail for list at center1 will also go to the all users of that list
at center2 and when the mail will reach center2 when it will be delivered
it will also be delivered to same list at center1 as that list of center1
is subscribed to the same list at certer2. This loop will continue.

I want to explain that why this condition is necessary. I want that when a
user at center1 sends a mail to list at that center it should go to all
users or that center locally through that mail server at that center. And
one copy should also go to the same list at other center center2. And same
condition I want at other center center2.  

If we use a only mail server at only one center say center1 then the
problem is that then if the user at center2 sends mail to any list mail
will first come at mail server at center2 then it will go to mail server
at center1 and then back it will go to mail server at center2 and it will 
be delivered to all users of center2 that are subscribed to this list . I
want that mail to users of center2 that are subscribed to list should go
directly with using the mail server at center2 and after that mail should
go to users of list at center1 using mail server at center1.

Is there any solution to this problem of looping?       
Can Mailman handle situations like this?
Any comments and suggestions are welcome. 

Arshad Mahmood.