Linux mail server email monitoring program - Compensation: tbd in Passaic, New Jersey

http://www.anarchomoney.com/jobs/linux-mail-server-email-monitoring-program/
Job Description
We need a method -- either a program or some scripting that can read each email that goes through a Linux Sendmail / Exim / Postfix server: We need a piece of software or a script that will record the following information for every email message that goes through.
* Sender
* Recipient
* Subject
* Message ID
* message sent date
* attachments y/n
* message size
also if possible;
* number of unread messages in inbox
* number of read messages in inbox
we do not need anything else at this point simply a file of one line for each email sent.
We do not need spam or antivirus software -- this is irrelevant
We know can do this in many ways. We are interested in the developer telling us the best way to do this.
The budget is up to you to advise us.
Skills Required:
linux, sendmail, exim, postfix, mail-servers