On networks with IP v6 enabled when running an "Exchange Server Health" test you receive a similar warning for "Network availability" to the one below.
Unexpected result returned by reverse DNS lookup. Ping results are retrieved using IP address therefore they may be incorrect.
Reverse DNS lookup returned host name 2002:3f40:3c19:8000:0:5efe:10.10.10.6 for IP Address 2002:3f40:3c19:8000:0:5efe:10.10.10.6 instead of expected mail01.test.com.
Ensure there is no IP address conflict.
Reverse DNS lookup details:
Netbios server name: mail01, fully qualified server name: mail01.test.com.
Fully qualified name mail01.test.com. was resolved to IP address 2002:3f40:3c19:8000:0:5efe:10.10.10.6 by DNS server.
IP address 2002:3f40:3c19:8000:0:5efe:10.10.10.6 was resolved to the server name 2002:3f40:3c19:8000:0:5efe:10.10.10.6.