The subject decides whether anything else exists. It should name the thing, not hint at it. A subject that reads as a riddle gets answered with a question, if at all.
The first line proves you know who you are writing to. If it could be sent to anyone, it will be treated as if it was.
The middle names the outcome in the reader's terms, not yours. The last line asks for something small.
Read the whole thing as the recipient, on a phone, with eleven other emails behind it. Most drafts do not survive that.
How we do it
The copy and the sequence are signed off by you in writing before anything sends, and you can change them at any time for messages that go out after.