R=dnslookup defer (-1): host lookup did not complete

[lamnian]

Hello,

Randomly Exim returns an error when trying to send an email

R=dnslookup defer (-1): host lookup did not complete

So when I try a nslookup I get the following

;; Got SERVFAIL reply from 127.0.0.1, trying next server
Server: ::1
Address: ::1#53

** server can't find somedomain.com: SERVFAIL

Then I rerun the nslookup and I get

Server: 127.0.0.1
Address: 127.0.0.1#53

Non-authoritative answer:
Name: somedomain.com
Address: the.correct.ip.address

Then I start the exim queue again and the mail is sent successfully.

Any ideas?