Not a senderscore person... but this is likely this is the result of an
end user reporting an old email as spam instead of deleting it.
I would hazard the FBL generates based on the date the use takes an
action regardless of how old the message is - it likely doesn't even
look at the original
Just arrived in the fbl mailbox..
This is a Mail.Ru Abuse Report for an email message received from domain
.com, IP 104.128.152.18, on Sat, 24 Mar 2018 06:00:01 +.
Version: 1
Original-Mail-From: Ðврора
Source: Mail.Ru
Abuse-Type: complaint
Subscription-Link: https://fbl.returnpath.