Archiving solution

We need an application in which we can scan documents save emails (deferent correspondence), store and categories, example we have a fax we scan it and then add it to the data base in the software and with it we add a description and open a case in which after that we will respond to that fax and they respond back and we have an ability to action this correspondence as closed or a reminder , also if we need any information on a certain correspondence we can just recall all previous history, and it’s a multi user application and with deferent access levels (example: this correspondence is confidential only the user x can access it) to this tree we can add the email messages related to the same correspondence it can be ? web based intranet or sql or any other suggested solution, with searching tools through all the database, based on any type of information, date, subject, correspondence author starter …etc