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ThreatOther

Fake Re:/Fwd: subject with no In-Reply-To header (thread hijack)

thread-hijacking

What this tier means

High-confidence threat indicator — phishing, impersonation, BEC, or scam pattern. Strong contributor to the trash decision.

How Gorganizer detects this

Subject line has a "Re:", "Fwd:", or multilingual equivalent (SV:, AW:, TR:, VS:) suggesting the email is a reply or forward, but the email has NO In-Reply-To or References header. Every legitimate email client automatically adds In-Reply-To when composing a reply — its absence is a strong indicator that the sender manually inserted the reply prefix to make their email appear to be part of a trusted conversation thread. This is a classic social engineering trick used in phishing, BEC fraud, and malware delivery campaigns. Score: +3 trash.

False-positive guard

Every signal in Gorganizer feeds a multi-module score — never a sole verdict. This is a threat-tier signal — it adds a strong contribution to the trash score. The full pipeline still requires convergence across multiple modules + a margin over the safety floor before deletion happens, and Gmail's trash (30-day recovery) is always used — never permanent delete.

About the scoring engine

Gorganizer's scoring engine emits over 1,800 signals across six modules — headers, sender, subject, body, attachments, and structural metadata. Every email is scored by every module independently; the final verdict requires multiple modules to agree and the trash score to beat the safety floor by a margin.

Sacred safety guards — never delete starred emails, replies, calendar invites, receipts/invoices, or attachments — apply unconditionally regardless of any signal.

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