[Systeme] Undelivered Mail Returned to Sender

This is the Postfix program at host lipn-sf1.lipn.univ-paris13.fr. I'm sorry to have to inform you that the message returned below could not be delivered to one or more destinations. For further assistance, please send mail to <postmaster> If you do so, please include this problem report. You can delete your own text from the message returned below. The Postfix program <martinez@lipn.univ-paris13.fr>: host mail.lipn.univ-paris13.fr[10.10.0.254] said: 550 5.1.1 <martinez@lipn.univ-paris13.fr>: Recipient address rejected: User unknown in local recipient table