An AI email summarizer is a tool that uses a language model to condense long email threads into short, readable summaries. It may process message bodies, quoted replies, and sometimes metadata to produce a quick overview for users, support teams, or executives.
In cybersecurity, this matters because the summarizer must handle untrusted content. If attacker-controlled email is fed into the model without strict separation between data and instructions, the thread can contain prompt-injection payloads that influence the summary or steer connected tools. Defenders reduce this risk by treating email as untrusted input, keeping system instructions separate, stripping hidden or non-rendered content, limiting any downstream actions with least privilege, and verifying critical decisions before acting on AI-generated summaries.