[exim] dnsbl question.. njabl

I just ran a debug test..

DNS list check: combined.njabl.org
new DNS lookup for 254.87.72.64.combined.njabl.org
DNS lookup of 254.87.72.64.combined.njabl.org (A) gave TRY_AGAIN
254.87.72.64.combined.njabl.org in dns_again_means_nonexist? no (option
unset)
returning DNS_AGAIN
LOG: dnslist_defer MAIN
DNS list lookup defer (probably timeout) for
254.87.72.64.combined.njabl.org: assumed not in list
drop: condition test failed

assuming njabl.org is down.. are there dnsbl timeouts in exim?