This is a system to prevent unwanted mail from reaching our mailbox. The system must have a list of authorised users, unauthorised users and unknown users for each mail account, and this list must be editable by the user at any time through a web interface or through an email sent to the mail server. It must have a simple interface for inserting new users and each user has to have a control center to manage his/her options. The idea is to have a challenge-response system to validate unknown users. Architecture of the system The system sits in a server independent of the end user and the mail server. The server name will be named [login to view URL] in the remainder of this document. The user has to supply all email configuration information to antispam.incentral.com. Then, the end user mail configuration will be changed to the new values: [login to view URL] will be replaced by [login to view URL] com, oldusername will be changed to newuser@antispam, and the password will probably stay the same. [login to view URL] checks for new mail every hour at the old mail server. If the user has messages from authorised users, then [login to view URL] stores them for download next time the user connects. If it has mail from unauthorised users, it either deletes them or tags them in the subject line with ***SPAM***, depending on the user configuration. If it has mail from unknown users, it sends then a reply from the user account with "Re:" and the mail title, with a message such as "This is an automated reply from the antispam system at incentral. Please veruify that you are a human user by clicking on the follwing link and replying to a simple, non-machine readable question". The user will be sent to a web page, which will have the image of a dog, and will have a combo box with 30 alternatives, one of which will be "dog". A spam system will not be able to tell a dog picture automatically, while a human will find it very easy. If the test is passed, the user is automatically put in the authorised users mail list, and if not, then either the message is deleted or tagged as spam. If there is no reply, then either it is deleted or tagged as spam. When the user of the system sends a mail to someone, the email goes through [login to view URL], and the recipient of the message is automatically added to the authorised users list.
## Deliverables
1) Complete and fully-functional working program(s) in executable form as well as complete source code of all work done. 2) Installation package that will install the software (in ready-to-run condition) on the platform(s) specified in this bid request. 3) Complete ownership and distribution copyrights to all work purchased.
## Platform
Windows 2000, IIS, SQL server or MySQL