we have on our server sympa with postfix installed. Everything was working fine for about 6 months. On our server were about 100 lists with the format listname@foobar.de Since yesterday the format of all lists is listname@intern.foobar.de (intern.foobar.de is the Sub-Domain where Sympa is running).
When sending a mail to listname@foobar.de I get the error mail from sympa "List "listname" does not exist".
Our normal E-Mail Adresses (surname.lastname@foobar.de) are working fine.
I'd be grateful for hints what could have lead to this problem and how to solve it.