this host is a 'poor' score for a reason - whether it's quasi-legitimate spam / marketing mail or a sharp statistical increase in mail volume over a short period due to some bot net or virus traffic - there's not supposed to be any misinformation or false positives. there are many reasons or factors that contribute to the score, which is mostly confidential for us (IronPort). we can tell you that it is a rolling average that is continuously correcting itself.
many cusgtomers are comfortable referring their partners or owners of incoming MTAs that have been rejected by SBRS to just RTM at senderbase.org and contact SB support teams for more info.
so in short, if you 'trust' this MTA and they don't want to contact SenderBase for help, then yes, manually add it to the whitelist. occasionally whitelisting is easier than constantly blacklisting, which is why senderbase is so cool / popular.
more info on senderbase.org and our 'Sender Base Reputation Score':
Table of ContentsIntroductionVersion HistoryPossible Future
UpdatesDocuments PurposeNAT Operation in ASA 8.3+ SectionsRule Types
Network Object NATTwice NAT / Manual NATRule Types used per SectionNAT
Types used with Twice NAT / Manual NAT and Network Obje...
[toc:faq]Introduction:This document describes details on how NAT-T
works.Background:ESP encrypts all critical information, encapsulating
the entire inner TCP/UDP datagram within an ESP header. ESP is an IP
protocol in the same sense that TCP and UDP are I...