I work as an IT guy in a law firm. I am recently asked to make a system wherein all the outgoing emails coming from our server to our clients will be put on hold first and wait for approval before it gets sent to the client.

Our mail server uses Exim (that's what it says in cPanel). I am planning to create filters where the outgoing emails will be forwarded to an editor account. Then, the editor will review and edit the contents of the email. When the editor already approves the email, it will then get sent to the client by the editor but still using the original sender in the "From:" and "Reply-To:" field.

I found some pointers from this site => http://www.devco.net/archives/2006/03/24/saving_copies_of_all_email_using_exim.php.

Once the filters are in place, I want to make a simple PHP interface for the editor to check the forwarded emails and edit them if necessary. The editor can then click on an "Approve" button that will finally deliver the message using the original sender.

I'm also thinking that maybe a PHP-less system will be enough. The editor can receive the emails from his own email client edit them and simply send the email as if he is the original sender.

1. Is my plan feasible?
2. Will there be issues that I have overlooked?
3. Does it have the danger of being treated as spam by the other mailservers since I'll be messing up the headers?