All our 5 server are configured for RBL or DNSBL with Exim which can be found at:
http://forums.ev1servers.net/showthread.ph...?threadid=34689

Everything was working great for last 6 months and now a lot of entires like:

2004-11-10 14:08:39 DNS list lookup defer (probably timeout) for 5.97.85.68.dnsbl.njabl.org: assumed not in list
2004-11-10 14:08:28 DNS list lookup defer (probably timeout) for 180.115.50.200.bl.spamcop.net: assumed not in list
<...>

Anuone knows why it happens ?
There is nothing wrong with configuration all 5 servers were working fine and now fails.