[Exim] puzzle with exim 4.14...

I'm fully aware that the logging was added at this version but am puzzled
as to what might be causing the following log entry since it occurs every
day all on all machines running 4.14. There are no other log entries that
might be associated...

no IP address found for host 209.237.12.112.29

Any ideas?

Thanks

--
Alan Thew                                       alan.thew@???
Computing Services,University of Liverpool      Fax: +44 151 794-4442