Answer: Please review our suggestion for paving over the muddy area where students wait before school.
Explanation: The revision mentioned above makes the sentence's tone appropriate for a from e-mail. The sentence's tone sounds polite and professional at the same time. As the mail is being sent to an authority (understood from the first look of the question given), it should be neat, polite, and have a professional or formal touch and it should not have a commanding tone. The mail would look more convincing and considerable if you can add convincing words like please, requesting, may, etc.