[exim] Postmaster is flooded by freeze notifications

Hi there,

some customer has produced quite a lot of bounce mail that cannot be
delivered because the recipient's network is unreachable. That means
that postmaster is notified as soon as Exim gives up, as there is no
sender for the bounce message.

Is there a proper way to handle this? Is it wise to just discard any
freeze notifications (I don't think so)?

What do you do in such cases?

Thanks for your help
Peter