Message bizarre ?

Bonjour,

j ai recu cet e-mail delivré par Mail Delivery System <MAILER-DAEMON@mx1.hrnet.fr>

This is the Postfix program at host mx1.hrnet.fr.

I'm sorry to have to inform you that your message could not
be delivered to one or more recipients. It's attached below.

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 attached returned message.

The Postfix program

<devotie@hrnet.fr>: host merak-g-1.hrnet.fr[212.94.223.56] said: 550 5.1.1
<devotie@hrnet.fr> User unknown; rejecting (in reply to RCPT TO command)

c est la premiere fois que je recoie sa de plus le dernier message envoyé date du 7 /12
que pensez vous de ce message ?
merci