[Mailman-Users] New lists fail... Do I need to create aliases for Exim?

[Andrew Steele]

Back in September I asked some questions about problems I was having 
getting Mailman running on the virtual server supplied by my ISP.  
Configuration was complicated by the fact that I do not have full 
admin access to the server.

Anyway, with some effort we have finally resolved most of the issues 
with one exception.

The initial test list created during installation works just fine.  
All the problems previously identified have been fixed.

However, if I access the web based interface and create a new list 
the the following occurs.

Upon subscribing addresses, each person receives as expected a 
welcome Email.

However, when sending an Email to the list address the message sent 
bounces back with the desination reporting

     Status: 5.5.0
     Diagnostic-Code: smtp;550-Callout verification failed:
     550 550 Unrouteable address

I'm presuming that the web interface is not creating aliases or some 
such thing.

I see that in the ALIASES file there are a series of entries relating 
to the test list but not the other lists created via the web 
interface. However, I was advised that the mailer used by the ISP 
does not require aliases.  

The mailer at the ISP is Exim 4.43.  

If I can advise the ISP tech guys on the necessary fix then that 
would probably speed up a fix so any advice gratefully received.  
Equally, I'd be pleased to apply a fix myself provided it does not 
require root access.  

Thanks in advance.

Andrew