[Exim] Secondary MX server rejecting mail immediately v2.11

I run a mail server that is secondary MX for a customer. The theory
is that is their mail will sit with us if their mail system goes down.

As I understand it however our exim will reject incoming mail for
servers that have been down for a long time. Whereas I would like
to accept that mail, queue it and eventually deliver it if the retry
time allows.
I am getting "retry time not reached for any host after a long failure
period".

Martin Stewart

______________________________________________
Martin Stewart
BTNet & MDIP Technical Support Manager
martin.stewart@???