[Exim] RETRY configuration

I would like to configure the retry values so that if the message is
from a local person then the warning would be issued very quickly
if the mail was not delivered to our local mail server e.g. quota
problems.

However my reading of the manual is that the first argument can be a
regular expression but with the local_part@domain as input.

I would like the equivalent of

if ($sender_domain = *.abdn.ac.uk) warn immediately

otherwise normal warning times.

Is this possible?

John Linn (j.linn@???)