You are using regular expressions to analyse data loss scenarios in email.
The FileReader logs show this type of entry:
Class: com.vontu.messaging.chain.MessageChain
Method: run
Level: SEVERE
Message: Message chain #5 encountered an unexpected error processing a message.
java.lang.StackOverflowError
at java.util.regex.Pattern$Branch.match(Pattern.java:4606)
at java.util.regex.Pattern$GroupHead.match(Pattern.java:4660)
at java.util.regex.Pattern$Loop.match(Pattern.java:4787)
at java.util.regex.Pattern$GroupTail.match(Pattern.java:4719)
An errant regular expression in one of the active policies
14.6 MP3, other environments may also be affected
This was identified by deactivating 50% of the policies then retesting. Iterating this process until the policy was identified and then taking the same approach with the Regular Expressions within that policy.