With most email programs, this small change will not be evident when you view the message because they usually show only a few header lines, like Date:, To:, From:, and Subject:.
If you would like to see the header line containing the spam score, you’ll need to have your email client program display the full details of the message headers.
Here is an example of what you might find: The spam score is indicated by “Probability=66%.” The “Gauge” is a Roman numeral representation of the spam score, which can be handy to use for comparisons in setting up filter rules.
“Report” lists keywords for the message characteristics that determined the spam score.
https://uwindsor.teamdynamix.com/TDClient/KB/Article Det? ID=10728 How to manage Approved/Blocked Senders lists in Pure Message spam filter?