ELECTRONIC MAIL PROCESSING UNIT INCLUDING SILVERLIST FILTERING
First Claim
1. A process for filtering messages, comprising:
- receiving a message envelope sent from a sender IP address, where the message envelope includes a sender address and at least one recipient address;
determining the reputation of the sender IP address;
allowing the message when the sender has a reputable sender IP address, irrespective of the sender and recipient addresses; and
performing a test when the sender IP address has unknown reputation, the test comprising;
issuing a temporary failure to the sender; and
detecting as a retry a message envelope received within a predetermined time period, where the sender and recipient addresses of the original message envelope and the received message envelope correspond; and
allowing the retry message.
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Accused Products
Abstract
Systems and methods of filtering received messages to discard unsolicited messages using silverlist filters and combinations of silverlist filters and other types of filters are disclosed. In many embodiments, an appliance remote from a mail server is used to filter messages using at least a silverlist filter prior to forwarding messages to the mail server. In a number of embodiments, a mail server applies a filtering process that includes a silverlist filter and a challenge response filter. One embodiment of the method of the invention includes receiving a message envelope sent from a sender IP address, where the message envelope includes a sender address and at least one recipient address, determining the reputation of the sender IP address, allowing the message when the sender has a reputable sender IP address, irrespective of the sender and recipient addresses, and performing a test when the sender IP address has unknown reputation. In addition, the test includes issuing a temporary failure to the sender, detecting as a retry a message envelope received within a predetermined time period, where the sender and recipient addresses of the original message envelope and the received message envelope correspond, and allowing the retry message.
38 Citations
34 Claims
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1. A process for filtering messages, comprising:
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receiving a message envelope sent from a sender IP address, where the message envelope includes a sender address and at least one recipient address; determining the reputation of the sender IP address; allowing the message when the sender has a reputable sender IP address, irrespective of the sender and recipient addresses; and performing a test when the sender IP address has unknown reputation, the test comprising; issuing a temporary failure to the sender; and detecting as a retry a message envelope received within a predetermined time period, where the sender and recipient addresses of the original message envelope and the received message envelope correspond; and allowing the retry message. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. A mail processing unit, comprising:
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a network connection configured to receive connection information, message envelopes, and message data, where the connection information includes a sender IP address, and message envelopes include a sender address and a recipient address; and a processor configured to determine the reputation of the sender IP address of each message; wherein the processor is further configured to allow messages from senders having reputable sender IP addresses; and wherein the processor is further configured to perform a test on messages from senders of messages having an IP address of unknown reputation, comprising; transmitting a temporary failure message via the network connection to the sender of the a message having an IP addresses of unknown reputation; detecting as a retry a message envelope received via the network connection within a predetermined time period, where the sender and recipient addresses of the original message envelope and the received message envelope correspond; and allowing the retry message. - View Dependent Claims (19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34)
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Specification