A query letter has one job: get someone to ask for the script. It is not a pitch document, not a synopsis, and definitely not a plea. One short paragraph, one clear ask, no attachments unless they were requested.
Structure it in three moves. Why them, specifically — name a film they made and a real reason your script belongs beside it. What it is — title, genre, page count, and the logline. Who you are — one sentence of relevant credibility, and if you have none, say nothing rather than inventing a hobby résumé.
Specificity is the entire filter. Executives and managers can tell a personalised query from a merged mailing in three seconds, and mass mailings are deleted at that speed. Ten researched queries outperform two hundred generic ones, consistently.
Track and follow up once. A polite single follow-up after two to three weeks is professional; three follow-ups is a reason to be remembered badly. Keep a simple log of who, when, and what they said, because the answer 'not this one, send the next' is a win.