[exim] SMTP callbacks and greylisting

Hello,


I have searched the archives for that matter but wasn't able to find
something applicable.

In fact, I'm quite p****d about folks using greylisting in a way
that SMTP callbacks are rendered useless: we reject mail temporarily
since the callback is deferred by greylisting at the sending site.
Due to a[nother] broken setup there, their enduser doesn't get
informed about the non-delivery. No second delivery is attempted
from the remote site. My question now is: is there a way I can make
exim overcome this situation? Maybe delaying the incoming SMTP in
order to shoot off a second callback attempt after a while, hoping
that bl**dy greylisting became satisfied in the meantime?

I really do disapprove working around pure stupidity and right now
I'm trying hard to locate someone responsible at that site but maybe
there is a more a less easy way of tweaking exim to cope with it
temporarily? Any hint is greatly appreciated!

TIA
vt

PS: Who will join setting up "ihategreylisting.org" ? ;)