[imp] Email redirects to remote addresses do not work.

[zyrixx]

Hello dear Horder User, I have tied Horde to a mail server (Postfix), 
which acts as a smart host. As soon as I forward mails to internal 
users, that's no problem.

But if I use an address that does not exist on the mail system, the mail 
server is instructed to send the mail via the recipient's Smtp server.

This makes no sense, because you can send mail to all remote addresses, 
always using the deposited Smtp server of the sender. Can it be that 
Horde passes the redirects wrong?