Abstract: Systems and methods for detecting content similarity in email documents are disclosed. In one embodiment, a method comprises generating a first token value for each of a plurality of character sequences of a first email document, selecting a first subset of the plurality of character sequences based on the first token values, and generating one or more hash values corresponding to the selected first subset of character sequences. The method further comprises generating a second token value for each of a plurality of character sequences of a second email document, selecting a second subset of the plurality of character sequences based on the second token values, and generating one or more hash values corresponding to the selected second subset of character sequences. The method additionally comprises comparing the one or more hash values corresponding to the selected first subset with the one or more hash values corresponding to the selected second subset.

Abstract: Systems and methods for detecting email content containment are disclosed. In one embodiment, a method comprises generating a first set of hash values corresponding to a first email document, wherein the first set includes a respective hash value corresponding to each of a plurality of character sequences of the first email document. The method further comprises generating a second set of hash values corresponding to a second email document, wherein the second set include a respective hash value corresponding to each of a plurality of character sequences of the second email document, and determining whether the first set of hash values is a subset of the second set of hash values.

Abstract: Systems and methods for efficiently identifying emails with content similarity are disclosed. In one embodiment, a method comprises grouping a first set of a plurality of email documents with only common-type subsets of character sequences in a first searchable group, and grouping a second set of the plurality of email documents with one or more uncommon-type subsets of character sequences in a second searchable group. The method further comprises selectively searching either only one of or both of the first and second searchable groups, and identifying selected one or more email documents of the plurality of email documents that may contain content that is similar to the particular email document based on the searching.

Abstract: A system and a method for detecting content similarities in different emails employing selective truncation are disclosed. In one embodiment, a method comprises generating a first token value dependent on a first subset of characters at a beginning portion of a first email document, generating a second token value dependent on a second subset of characters at an ending portion of a first email document, and depending upon the first and second token values, selectively generating one or more hash values corresponding to a sequence of characters between the first subset and the second subset.

Abstract: Systems and methods for detecting email content containment are disclosed. In one embodiment, a method comprises generating a first set of hash values corresponding to a first email document, wherein the first set includes a respective hash value corresponding to each of a plurality of character sequences of the first email document. The method further comprises generating a second set of hash values corresponding to a second email document, wherein the second set include a respective hash value corresponding to each of a plurality of character sequences of the second email document, and determining whether the first set of hash values is a subset of the second set of hash values.

Abstract: Systems and methods for detecting content similarity in email documents are disclosed. In one embodiment, a method comprises generating a first token value for each of a plurality of character sequences of a first email document, selecting a first subset of the plurality of character sequences based on the first token values, and generating one or more hash values corresponding to the selected first subset of character sequences. The method further comprises generating a second token value for each of a plurality of character sequences of a second email document, selecting a second subset of the plurality of character sequences based on the second token values, and generating one or more hash values corresponding to the selected second subset of character sequences. The method additionally comprises comparing the one or more hash values corresponding to the selected first subset with the one or more hash values corresponding to the selected second subset.