Web admin: Can't add a distribution list

[Alvin]

On 12/01/2012 13:23, Alvin wrote:
> Hello,
>
> I can't add a certain distribution list to the system.
> [...]
>     LDAP Error: Could not add object
> cn=protocol at example.com,dc=example,dc=com: Type or value exists

I have found the problem. It has nothing to do with the name 'protocol'.

That mailing list (and others) contain multiple addresses that belong 
the the same people. I have added those people in the Addressbook. Some 
of them have aliases. A distribution list can't contain multiple 
addresses from the same person.

Aside from telling people to use 1 account, or creating 'John Doe2' in 
the addressbook, is there another solution?