Email service expert required

We have a special need to track our incoming emails and outgoing emails so we can track how long it takes a support person to reply to an email question.
We do not want to use a traditional help desk solution. We need to be able to tie this into our existing methods which is using outlook to send and receive emails. Example: support person received an email with a question. Support person replies to that email using their outlook email. We need to know how long it took for that reply to be sent in response to the incoming email. I can give more details later if the right freelancer is found. We could pay by the project or by the hour on a consulting basis. If you bid on this project include the words Orange Emails Only in your response or it will be ignored