[Exim] no IP address found for host <localdomain>

Hello Exim Experts;

I get through my /var/log/maillog and I found I have lots of similar
this kind of messages:

Aug 3 17:47:24 ms1 exim[4788]: 2004-08-03 17:47:24 no IP address
found for host acme.com.ac (during SMTP connection from
mgeXXX.perfge.com [38.112.197.11]:64352)


what does it mean? any impact in my mail receiving and delivery?

Note that acme.com.ac is my domain

Your feedback is very much appreciated.

Regards,
Sean