Introducing PhishNet Harpoon: Hunt Email Threats Across Your Whole Tenant

When a phishing email slips past your defences, the clock starts. The same message has often landed in dozens or hundreds of mailboxes, and every minute it sits there is another chance for someone to click. Yet the traditional response is painfully slow: check one inbox, then the next, then the next, hoping you find every copy before anyone acts on it. Harpoon changes that.

PhishNet Harpoon brings powerful, tenant-wide email discovery and response right into your existing Phishing Tackle platform. Instead of chasing suspicious messages one mailbox at a time, your security and IT teams can search across connected Microsoft 365 environments from a single place, and act on what they find at scale.

Search your whole tenant in one place

Create a Harpoon search using flexible criteria such as subject, sender, recipient, body content, attachments, and lookback period. Matching messages are collected automatically in the background, so you are not left refreshing a screen or exporting logs. Within moments you have a clear picture of how far a threat has spread, across every connected mailbox, from a single console.

From discovery to action

Finding the messages is only half the job. From the results, you can review what Harpoon has gathered and take bulk action, including quarantine, to contain the risk quickly during a live incident. One search, one decision, and the offending email is pulled from every mailbox it reached, rather than being removed by hand one account at a time.

Built for real security operations

Harpoon is designed for the way incident response actually works. It gives you fast investigation during an outbreak, consistent handling across the whole organisation, and a compliance audit trail that records exactly what was searched and what actions were taken. Whether you are responding to a reported phish, hunting a wider campaign, or cleaning up after an incident, Harpoon helps you move from discovery to action with confidence, and with a record you can stand behind.

What you can do with Harpoon

• Search every connected Microsoft 365 mailbox at once, using subject, sender, recipient, body content, attachments and lookback period.
• See the full spread of a threat automatically, without exporting or stitching together logs.
• Review matching messages and quarantine them in bulk to contain an incident fast.
• Keep a complete audit trail of what was searched and what was actioned, for compliance and reporting.

Key takeaways

• Harpoon adds tenant-wide email search and response to the Phishing Tackle platform, so you no longer have to work mailbox by mailbox.
• Flexible search criteria surface every copy of a suspicious message across connected Microsoft 365 accounts in the background.
• Bulk actions, including quarantine, let you contain a live incident in a single step.
• A built-in audit trail records every search and action, supporting consistent handling and compliance.

Phishing Tackle offers the tools businesses need to strengthen their human risk strategies, with multi-platform testing, real-time behavioural insights, and actionable data to keep your organisation ahead of modern cyber threats.

Contact us today to learn how Phishing Tackle can help safeguard your organisation from the growing array of cyber risks.