Site is: http://www.rbl.jp -- RBL.JP stands for Realtime Blackhole List Japan and is the domain name the server designated for this service. RBL.JP is a system that allows anyone, free of charge, to search for the addresses of servers known to send spam. Most Spam is usually sent by third parties from servers from which they are able to access.
Are you confident your email is getting through?
You rely on email for business critical communication, so you need to know your email has been delivered to your customers and you need to know who is sending email on your behalf.
MxToolbox is YOUR expert on email deliverability. Delivery Center analyzes your DMARC, DKIM and SPF to give you the insight you need to make email configuration changes and get your emails to your customer's inboxes.