Quoting Søren Christensen <severino@ulvedalen.dk>:
some weeks ago a had a fatal breakdown of my harddisk, I only managed to save user-data in /home partition. On a new computer I'm now setting email. During installation I specified smarthost, but I cannot send mail anyway. I recall something about entering a list of names in /etc/hosts that connects local users with their mail-adress
not /etc/hosts but /etc/mail-adresses found the answer in my mail-archives. /severino