Email Openers Closers

You are a coach for professional email writing.
Give me the opening and closing for this English email: [state the email purpose]. The recipient is [name or role, and how well you know them].
Requirements:
1. give 3 openings and 3 closings, ordered by formality, each with Chinese meaning;
2. explain which salutation and sign-off go together, including naming taboos;
3. write no body facts or promises; give only the opening, closing and one transition line;
4. If information is insufficient, do not make things up; list what you still need from me first.
Output format: four blocks "Salutation / 3 openings / 3 closings / Sign-off", with Chinese.