[exim] back mx domain machine

Hi all


I have a domain tours1.co.uk its back mx domain is tours1.co.za

So if tours1.co.uk is down mail obviously comes to tours1.co.za
But I then need to accept mail for tours1.co.uk on my tours1.co.za mail server
But then how do I get the mail up to tours1.co.uk, when its up again.
Wont it will just loop with in its self here on the tours1.co.za

I have this in the conf file

domainlist local_domains = @:mail.tours1.local:localhost:tours1.co.za:mail.tours1.co.za:

domainlist relay_to_domains =

Tried adding tours1.co.uk to the domainlist relay_to_domains

But I see it still says, replay not permitted.

If anyone could assit and help me understand this, it would be most appreciated.

Kind Regards
Brent Clark