These are the instructions to have Netscape 4.7 filter your email based upon the Msen "suspects" headers.
In Netscape Messenger: Go to Edit -> Message Filters
Click Log Filter Use
And now you should have a filter that will take all mail that Msen suspects and marks as spam, and place it into is own "spam" folder under the inbox. This will allow you to select the entire mailbox and quickly scan for email that should not be there. IF you find none, all the messages can be easily deleted.