outgoing mail deliverd locally and not to the internet

i have a little problem with my postfix. just set it up recently, used
sendmail before, but decided to switch to postfix for spamassassin.
running postfix 1.1.4 on suse linux 8.0, yes i know both old version, but
that doesnt change the facts...


the problem is... all the time, i want to send an email to an emailaddress
on the internet the local server just deliveres it locally and does not send
it to the internet. i guess the problem is, that the local servers name and
domain are 'genesis.massoth.de' and the servers domain on the internet is
'massoth.de'. How can i handle this problem... ???

now, if i send an email to 'myemail@massoth.de' it deliveres it locally. if
i send an email to 'myemail.special@massoth.de' which is another mailbox on
the server it comes back with 'Mail Delivery System Failure' because this
user does not exist on the local server... ??? Any sugestions?



greetings, Daniel