how to LUSER_RELAY in sendmail?

[Ries van Twisk <rvt@dds.nl>]

Hai, 

I need some more detaild information about the LUSER_RELAY option in sendmail.

if I use:
define(`LUSER_RELAY', `smtp:provider')dnl
for usernames with the correct domain but are not part if this domain
it must be relay'd to my ISP.
How do I prevent that a username get's the privider name after the @
example:
  ries@mydomain.nl
will become
  ries@providers-domain.nl
but it must be
  ries@mydomain.nl


Anyone can point me to a webside where LUSER_RELAY is more explaint in detail?
and/or solutions for my probs?

What happends if I do
  define(`LUSER_RELAY', [smtp:provider])dnl


Best Regards 

Ries van Twisk