Adding external users to distribution lists

[Alvin]

On 2015-06-25 17:32, Alvin wrote:
> Hello list,
> 
> I'd like to add mailing lists to a Kolab 3.4 server. The mailinglist (Kolab 
> distribution group (static)) will contain a mix of users with a local domain, 
> but mostly external domains.
> 
> [...]
>   'Primary Email Address' remains empty because of an error when trying to add 
> the address there: "Email address '....' not in local domain."

Could it be that this is causing other errors?
While looking at the documentation for any information about
distribution lists I found some command line commands.

# kolab list-mailboxes
  gives me a list of mailboxes

but

# kolab list-users
Traceback (most recent call last):
  File "/usr/sbin/kolab", line 39, in <module>
    kolab = Cli()
  File "/usr/lib/python2.7/site-packages/pykolab/cli/__init__.py", line
69, in __init__
    commands.execute('_'.join(to_execute))
  File "/usr/lib/python2.7/site-packages/pykolab/cli/commands.py", line
138, in execute
    commands[cmd_name]['function'](conf.cli_args, kw)
  File "/usr/lib/python2.7/site-packages/pykolab/cli/cmd_list_users.py",
line 36, in execute
    wap_client.authenticate(username=conf.get("ldap", "bind_dn"),
password=conf.get("ldap", "bind_pw"))
  File
"/usr/lib/python2.7/site-packages/pykolab/wap_client/__init__.py", line
68, in authenticate
    response = request('POST', "system.authenticate", post=post)
  File
"/usr/lib/python2.7/site-packages/pykolab/wap_client/__init__.py", line
375, in request
    response_data = request_raw(method, api_uri, get, post, headers)
  File
"/usr/lib/python2.7/site-packages/pykolab/wap_client/__init__.py", line
415, in request_raw
    return response_data
UnboundLocalError: local variable 'response_data' referenced before
assignment

Is it still possible to create mailing lists with Kolab in the first place?