Barracuda Email Security Service (ESS) now allows you to search for similar messages (based on the same sender and/or subject) using Barracuda Forensics and Incident Response (FIR). A link to the Forensics product is now available in the message view section and is called "Search for similar messages".
Example use case: Once you identify a message that is part of a phishing or spear-phishing attack, you can search for similar messages, using FIR, and then take remediation action like, delete those messages from the users’ mail boxes.
FIR works in conjunction with Barracuda Sentinel and Barracuda Email Security Service.
Barracuda Forensics
Barracuda Sentinel