[Exim] host lookup did not complete

/usr/local/sbin/exim -v -M 11xf0x-000AbO-00
delivering message 11xf0x-000AbO-00
LOG: 0 MAIN
== almada@??? R=lookuphost defer (-1): host lookup did not complete


yet, on the same host

% nslookup leopard.ebonet.net
Server: localhost
Address: 127.0.0.1

Non-authoritative answer:
Name:    leopard.ebonet.net
Address:  194.133.121.2

% telnet leopard.ebonet.net 25
Trying 194.133.121.2...
Connected to leopard.ebonet.net.
Escape character is '^]'.
220 leopard.ebonet.net ESMTP Sendmail 8.9.3/8.8.7; Wed, 15 Dec 1999 06:32:42 +0100
quit
221 leopard.ebonet.net closing connection
Connection closed by foreign host.