MX Backup and Advance Mail Routeing

[binover]

Hi all!
guys, I have a little problem, I'm missing something...
I'm trying to install a MX Backup server in one of our ISPConfig3 server.

I read here http://www.howtoforge.com/forums/showthread.php?t=40596 the way to do it is:

Being DOMAIN.NET the domain to backup MAIL.SERVER.NET the mail server and BACKUP.SERVER.NET the backup server

- Adding a MX record in the DNS Zone of the domain in MAIL.SERVER.NET to BACKUP.SERVER.NET with a higther priority.

Something like: dig mx DOMAIN.NET

MX 10 MAIL.SERVER.NET
MX 20 BACKUP.SERVER.NET

- Create in the back up server an "Advance Mail Routing - Mail Transport" pointing to the first mail server.

looking like:
Server: BACKUP.SERVER.NET
Domain: DOMAIN.NET
Type: smtp
No MX lookup: off
Destination: MAIL.SERVER.NET
Sort by: 1
Active: on

Ok, I done all of this and where I send an email, in the backup server mail log I'm getting:

NOQUEUE: reject: RCPT from lalala.lololo.net.[xxx.xxx.xxx.xxx]: 550 5.1.1 <binover@mailtest.net>: Recipient address rejected: User unknown in relay recipient table.....

That tell me the dns part it is ok but y have some bad config in the ispconfig backup server...

Can you help me? THANKS

[till]

You missed to add the users or domains that shall be relaey to the relay recipients table in the ispconfig mail module.