Readers can often tell when nobody was home while an email was being written. For example, Gartner reports that 49% of US consumers believe generative AI has made the quality of content worse.

The penalty grows with the relationship at stake. In a study of more than 1,100 US professionals, researchers from the University of Florida and USC found that over 80% saw supervisors as sincere when they used AI for light edits. That figure fell to between 40% and 52% for heavily AI-assisted messages, which should give any founder or account manager pause before automating a personal note to a client.

Accuracy is a separate headache, because an AI model will happily write “Final hours!” for a sale that actually runs until Sunday. Washington state’s email law saw nearly 200 class actions over subject lines like that after a 2025 court ruling. A 2026 amendment now requires proof that the sender knew a subject line was misleading, but saying “the AI wrote it” isn’t a defense that’s likely to work.

Inbox AI also changes who reads your email first. The majority of consumers now make decisions based on AI-generated summaries alone, so vague copy can easily get smushed into nothing before a person ever sees it. Ultimately, the safest move is to put your main point where no algorithm can miss it.