Sending Host Summary
Reverse DNS Hostname: Hostname of the sending host, as verified by reverse DNS (PTR) lookup.
IP Address: IP address of the sending host.
SBRS Score: (SenderBase Reputation Score). The range is from 10 (likely a trustworthy sender) to -10 (apparent spammer). A score of “None” indicates that there was no information about this host at the time the message was processed.