If the DNS for your hostname is not set up correctly, you may receive an email saying something similar to this:
Your hostname (srv.example.com) could not be resolved to an IP address. This means that /etc/hosts is not set up correctly, and/or there is no dns entry for srv.example.com. Please be sure that the contents of /etc/hosts are configured correctly, and also that there is a correct ‘A’ entry for the domain in the zone file. Some or all of these problems can be caused by /etc/resolv.conf being setup incorrectly. Please check that file if you believe everything else is correct. You may be able to automatically correct this problem by using the ‘Add an A entry for your hostname’ option under ‘DNS Functions’ in your Web Host Manager.
Most of the time, this error email is triggered by private name servers not being set up correctly. It could also mean there are missing, corrupted, or improperly formatted DNS records.