How a draft is written, and what is blocked

What is blocked outright

• Em dashes and en dashes, which are the most reliable single tell in a short message.
• Canned openers: "I hope this message finds you well", "I wanted to reach out", "I came across your profile".
• Marketing filler and the phrases language models reach for: "delve into", "rich tapestry", "unlock your potential", "circle back", "pick your brain".
• Manufactured empathy. "I imagine no two days look the same" is unfalsifiable, faintly patronising, and says nothing, which is exactly why it gets written.
• Any unfilled placeholder, which is the failure everybody has received at least once.

What forces a human look rather than blocking

• A draft that reuses a phrase from another recent draft. Two recipients may well know each other.
• A draft asserting something checkable, such as a figure. Every recipient is an expert on their own business, and a confidently wrong number costs more than saying nothing.

A message has a purpose, and the rules follow it

A public comment is not a pitch. Neither is congratulating somebody on a new job, nor the first line after they accept a request. Asking each of those to carry a call to action is what produces a comment that reads like an advert, so the rules differ by what the message is for.