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

I was facing some problems with my exim mail server after cpanel migration. I weren’t able to send and receive emails from all emails accounts under any domains on that migrated VPS.

How to check?
Create a test email account under a domain on that VPS.

Login to cPanel >> Mail accounts >> Create new >> [email protected]

Then try to send emails from that test account you have created and watch the exim log file via command line

[root@EcLinux]# tailf /var/log/exim_mainlog | grep [email protected]
2013-09-21 06:34:28 1VND1f-0006gu-J1 <= [email protected] H=(66.85.147.19) [127.0.0.1]:43456 P=esmtpa A=dovecot_login:[email protected] S=601 [email protected] T="Test mail" for [email protected]

Using Message ID from the above output check the mail queue log(exim -Mvl Message ID)

[root@EcLinux]# exim -Mvl 1VND1f-0006gu-J1
2013-09-21 06:55:32 Received from [email protected] H=(66.85.147.19) [127.0.0.1]:44445 P=esmtpa A=dovecot_login:[email protected] S=602 [email protected] T="Test mail"
2013-09-21 06:55:33 [email protected] R=dkim_lookuphost defer (-1): host lookup did not complete

Got the error “R=dkim_lookuphost defer (-1): host lookup did not complete”

Solution
Add these nameservers 8.8.8.8, 8.8.4.4 IP to the resolv.conf file will solve the issue.

[root@EcLinux]# vim /etc/resolv.conf
---------
nameserver 8.8.8.8
nameserver 8.8.4.4
~
~
~
:wq
---------

Thats it, I hope this solution will solve your issue.   🙂