Detect AI-Generated Emails

Why AI Detection in Emails Specifically Matters

Emails has distinctive conventions that make AI-generated versions unusually easy to spot — and unusually costly to miss. Readers, editors, teachers, and reviewers of emailsbuild mental models of what genuine, human-produced emails should sound like. AI tools, trained on massive generic corpora, often produce output that reads like an average of everyemails sample rather than a specific human's actual voice. That tension is exactly the signal AI detectors pick up.

The Specific Statistical Signals in Emails

Detection of AI-generated emails relies on three families of signal. First, perplexity — a measure of how "surprising" each token is to a reference language model. Emails written by humans tends to contain surprising phrasings, domain-specific jargon used naturally, and occasional awkward constructions that are statistically less likely. AI output, optimized for fluency, typically sits in a narrower band of predictable tokens. Second, burstiness — the variation between sentences. Human writers alternate between short punchy sentences and longer clause-rich ones; most AI output is more uniform. Third, stylometric fingerprinting against samples of known AI-generated content.

Known Limitations for Emails

No detector, ours included, achieves perfect accuracy on emails. Specific limitations include: short samples (under ~150 words) lack enough statistical evidence for reliable detection; content heavily edited by a human after AI drafting may pass as human; content written by non-native speakers, ESL students, or authors with unusually formulaic natural styles may produce false positives; and content from the newest AI model releases often evades detection until detectors are retrained against those specific models. Accuracy figures published on our statistics page reflect current benchmarks, not fixed guarantees.

Using EyeSift Results Responsibly

A "likely AI" result on a piece of emails is a signal, not a verdict. The responsible workflow combines detection output with human judgment, context, and corroborating evidence — drafts, revision history, direct discussion with the author, source interviews where applicable. Using detection output alone to make high-stakes decisions about a person's work (academic discipline, employment, publication retraction, editorial rejection) produces false-positive harm that damages trust in the verification process. Treat the score as one input among several.

Free, Private, No Sign-Up

EyeSift's detector for AI-generated emails is completely free, requires no sign-up, and imposes no per-analysis limits. Content you submit is processed and immediately discarded — we do not store, log, or use your emails for training our models. See our Privacy Policy for full data-handling disclosure. The service is supported by contextual display advertising.

Last reviewed: May 31, 2026. Detection techniques and accuracy figures are re-evaluated monthly. See our Methodology page for full technical detail.