[Exim] Copy every incomming Mail to a backup server

Hello,
you discussed this topic a short while ago,
but I can't find your answers in the archives ...

D e s c r i b t i o n:
I wanna copy every incomming mail to a backup server, thats all.
S o l u t i o n :
I could define a "shadow transport" for my "local transport" and write every message
to the backup server via nfs.
Q u e s t i o n s:
Is this solution clumsy is there a better way ?
Will exim4 support something like "remote shadow transport" ?



regards
Oliver