Rebuild the missing context
Assume the recipient will not remember every date, promise, or earlier conversation. For a message about how to follow up on missing client feedback, use this factual base: summarize the deliverable, version, requested input, owner, and effect on the schedule.
Say what needs to happen next
State the decision, information, or practical action you need and include a real deadline only when one exists. Give a small set of options and explain which default plan applies if the real deadline passes. Make the immediate next step clear enough that the recipient can answer without reconstructing the entire history.
Avoid making urgency into pressure
Do not bury a scope or price change, threaten the relationship, or pretend silence means approval. Use the contract and documented escalation route for legal, payment, privacy, or security decisions. Do not make the other person responsible for reducing the discomfort that prompted you to write.