Please check a memo

I have correct one of my student's memo. Could you help me check it to ensure its accuracy, fluency? Thank you! MEMO
To： All departments
From: Accounting department
Date: April 11, 2012
Subject: Overtime pay

In order to ensure yourovertime pay is accurate and reward you, Accounting Department needs to the information about your name who worked overtime and your overtime periods in March. So department managers' assistant present the information in an e-mail attched a file to Accounting Department before April 13. We will figure out their overtime pay and distribute it to salary card before April 20. Each department makes sure to submit the file as soon as possible. Thank you!