cant receive mails after upgrade and server switch

[DocSnyd3r]

Hi,
I installed RC3 an a new Server and importet the mail db and changed the status to toadd which added all my mail users. I can also connect via imap and if I copy ma mails over I can fetch them. But I can't send new mail, I get this error:

Code:

This is the mail system at host xxx.eu.
  
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 mail system
  
<stefan@xxx.eu>: unknown user: "stefan"

PS xxx.eu is also my FQDN is this a problem?

PPS DNS

Code:

    Sub    TTL    RR-Typ    Pref(MX)    Wert
Sub 1             MX     10     mail.xxx.eu.
Sub 2     *     14400     A         87.230.x.x