[Mailman-Users] Duplicate Emails to Members of Two Lists

[Jeff Grossman]

On Mon, 20 Dec 2010 10:14:53 -0800, "David Cunningham" <davec at mecnet.net>
wrote:
> Hi All,
> 
> I have a problem where users are listed on two separate lists, then  
> the same email is sent to both lists, and they get two copies.
> 
> For example, joe at test.com is on lists test1 at lists.test.com and  
> test2 at lists.test.com.  Dan at test.com sends an email to both  
> test1 at lists.test.com and test2 at lists.test.com.  So, joe at test.com get's  
> two copies of the same email, one from each list.
> 
> I know that the "nodupes" feature is only designed to stop duplicates  
> in the event that a user is specifically defined in the email.  For  
> example, it works great when dan at test.com sends an email to  
> test1 at lists.test.com and CCs joe at test.com directly.  Joe at test.com only  
> gets one copy.
> 
> But, I have users insisting that before I upgrade to the latest  
> version of Mailman, this also worked when users were on multiple lists.
> 
> Does anyone have any ideas?
> 
> Dave

You don't mention what version you are currently running.  You want to use
umbrella lists.  You can read more about it at
http://wiki.list.org/pages/viewpage.action?pageId=4030540.

Jeff