Bro you should stress test your server first before deployment and make sure you already ran BPA. You should at least maximize your exchange server by using outlook anywhere instead of POP3. Also, don't forget to follow the best practices on an exchange server in terms of system file location and storage locations for security and speed.
It's good to know daghan pod diay exchange admins diri (Dapat naay lahi nga thread). Anyway, good luck on your project.