War On Spam: Challenge/Response Filtering

Challenge/response filtering blocks unsolicited email messages and sends a challenge to the sender.

Internet Service Providers have a new technology now to avoid unsolicited email messages clogging up their consumers’ mail boxes.

This system checks whether the sender’s address or domain name is added to the recipient’s address book. If it is there the mail is delivered to the inbox of the recipient. If not, it is filtered and sent to a different folder.

The system also sends a challenge to the sender, a task, which automated machines cannot perform. If the sender is able to provide the required response the mail is sent to the recipient. Some systems send a message to the recipient to add the sender to the address book.

To read more about challenge /response filtering for spam control click here.