[EXIM] Problem with blocked sender (exim 1.92)

My configure has the following

sender_reject_recipients = @@dbm;/disk2/exim/tables/blocked-senders

and the file contains

go-tel.com : *

however a test session times out on the lookup during

mail from:<spammer@???>

and the `spam' is allowed through. Apart from possibly using

sender_verify = true

and/or upgrading, what else can I do?

Thanks

-- 
Alan Thew                                       alan.thew@???
Computing Services,University of Liverpool      Fax: +44 151 794-4442

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