# US 8,782,781 B2 · System for reclassification of electronic messages in a spam filtering system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,782,781 B2 - Document ID: US8782781B2 - Status: Granted - Kind: B2 - Application number: 12/754,523 - Filed: 2010-04-05 - Published: 2010-10-14 - Granted: 2014-07-15 - Earliest claimed: 2004-06-30 - Assignees: Google Inc. - Applicants: Daniel Wesley Dulitz; Seth Golub - Inventors: Daniel Wesley Dulitz; Seth Golub - Web page: https://patentgrep.com/patent/US8782781B2 ## CPC - H04L 51/212: using filtering or selective blocking - G06Q 10/107: Computer-aided management of electronic mailing [e-mailing] - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - G06Q: INFORMATION AND COMMUNICATION TECHNOLOGY [ICT] SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES; SYSTEMS OR METHODS SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES, NOT OTHERWISE PROVIDED FOR ## Abstract A method for indicating probability of spam for email comprises tracking network traffic characteristics for the email, and comparing the tracked characteristics for the email to characteristics for email from trusted or known spam sources. ## Claims ### Claim 1 A computer implemented method for filtering emails on a server system having one or more processors and memory storing one or more programs for execution by the one or more processors, comprising: receiving an email to a recipient from a sender; in response to receiving the email: determining whether there is a direct relationship between the sender and the recipient; and (i) when no direct relationship between the sender and the recipient is found, searching for an indirect relationship between the sender and the recipient, and utilizing the existence of the indirect relationship, when found, for determining a spam probability of the email by evaluating statistical information regarding the historical electronic interactions associated with the sender; and (ii) when a direct relationship between the sender and the recipient is found, determining a spam probability of the email by evaluating statistical information regarding the historical electronic interactions between the recipient and the sender using one or more non-email applications; and classifying the email according the identified spam probability. ### Claim 2 (depends on 1) The computer implemented method of claim 1, wherein determining the spam probability further comprises: combining historical electronic interactions from an email application and historical electronic interactions from the one or more non-email applications to produce a combined condition; and identifying the spam probability of the email based at least in part on the combined condition. ### Claim 3 (depends on 1) The computer implemented method of claim 1, wherein identifying the spam probability further comprises: identifying the spam probability of an email based on historical electronic interactions between one or more additional recipients and the sender. ### Claim 4 (depends on 1) The computer implemented method of claim 1, wherein the one or more non-email applications includes a plurality of: an instant messaging application, an on-line chat application, a file-sharing application, and a collaboration application. ### Claim 5 (depends on 1) The computer implemented method of claim 1, wherein: the statistical information relating to previous interactions between the recipient and the sender includes one or more of the following: types of interaction and frequency of interaction. ### Claim 6 A system, for filtering emails, comprising: at least one processor; and memory storing one or more programs to be executed by the at least one processor; the one or more programs comprising instructions for: receiving an email to a recipient from a sender; in response to receiving the email: determining whether there is a direct relationship between the sender and the recipient; and (i) when no direct relationship between the sender and the recipient is found, searching for an indirect relationship between the sender and the recipient, and utilizing the existence of the indirect relationship, when found, for determining a spam probability of the email by evaluating statistical information regarding the historical electronic interactions associated with the sender; and (ii) when a direct relationship between the sender and the recipient is found, determining a spam probability of the email by evaluating statistical information regarding the historical electronic interactions the recipient and the sender using one or more non-email applications; and classifying the email according the identified spam probability. ### Claim 7 (depends on 6) The system of claim 6, wherein instructions for determining the spam probability further comprises instructions for: combining historical electronic interactions from an email application and historical electronic interactions from the one or more non-email applications to produce a combined condition; and identifying the spam probability of the email based at least in part on the combined condition. ### Claim 8 (depends on 6) The system of claim 6, wherein instructions for identifying the spam probability further comprises instructions for: identifying the spam probability of an email based on historical electronic interactions between one or more additional recipients and the sender. ### Claim 9 (depends on 6) The system of claim 6, wherein the one or more non-email applications also includes a plurality of: an instant messaging application, an on-line chat application, a file-sharing application, and a collaboration application. ### Claim 10 (depends on 6) The system of claim 6, wherein: the statistical information relating to previous interactions between the recipient and the sender includes one or more of the following: types of interaction, media of interaction, and frequency of interaction. ### Claim 11 A non-transitory computer readable storage medium storing one or more programs configured for execution by a computer, the one or more programs comprising instructions for: receiving an email to a recipient from a sender; in response to receiving the email: determining whether there is a direct relationship between the sender and the recipient; and (i) when no direct relationship between the sender and the recipient is found, searching for an indirect relationship between the sender and the recipient, and utilizing the existence of the indirect relationship, when found, for determining a spam probability of the email by evaluating statistical information regarding the historical electronic interactions associated with the sender; and (ii) when a direct relationship between the sender and the recipient is found, determining a spam probability of the email by evaluating statistical information regarding the historical electronic interactions between the recipient and the sender using one or more non-email applications; and classifying the email according the identified spam probability. ### Claim 12 (depends on 11) The non-transitory computer readable storage medium of claim 11, wherein instructions for determining the spam probability further comprises instructions for: combining historical electronic interactions from an email application and historical electronic interactions from the one or more non-email applications to produce a combined condition; and identifying the spam probability of the email based at least in part on the combined condition. ### Claim 13 (depends on 11) The non-transitory computer readable storage medium of claim 11, wherein instructions for identifying the spam probability further comprises instructions for: identifying the spam probability of an email based on historical electronic interactions between one or more additional recipients and the sender. ### Claim 14 (depends on 11) The non-transitory computer readable storage medium of claim 11, wherein the one or more non-email applications also includes a plurality of: an instant messaging application, an on-line chat application, a file-sharing application, and a collaboration application. ### Claim 15 (depends on 11) The non-transitory computer readable storage medium of claim 11, wherein: the statistical information relating to previous interactions between the recipient and the sender includes one or more of the following: types of interaction and frequency of interaction.