A method, comprising: receiving an input from a user, wherein the user identifies content common to a plurality of email documents and specifies that the common content is to be disregarded; 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, and wherein the generating of the first set of hash values disregards any of the common content present in the first email document; generating a first bloom filter representing the first set of hash values corresponding to the first email document, wherein generating the first bloom filter includes setting one or more bits corresponding to and dependent on each hash value in the first set of hash values; generating a second set of hash values corresponding to a second email document, wherein the second set includes a respective hash value corresponding to each of a plurality of character sequences of the second email document, and wherein the generating of the second set of hash values disregards any of the common content present in the second email document; generating a second bloom filter representing the second set of hash values corresponding to the second email document, wherein generating the second bloom filter includes setting one or more bits corresponding to and dependent on each hash value in the second set of hash values; and determining whether the first set of hash values forms a smaller subset of the second set of hash values, by performing a bitwise OR operation on the first and second bloom filters. receiving an input from a user, wherein the user identifies content common to a plurality of email documents and specifies that the common content is to be disregarded; 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, and wherein the generating of the first set of hash values disregards any of the common content present in the first email document; generating a first bloom filter representing the first set of hash values corresponding to the first email document, wherein generating the first bloom filter includes setting one or more bits corresponding to and dependent on each hash value in the first set of hash values; generating a second set of hash values corresponding to a second email document, wherein the second set includes a respective hash value corresponding to each of a plurality of character sequences of the second email document, and wherein the generating of the second set of hash values disregards any of the common content present in the second email document; generating a second bloom filter representing the second set of hash values corresponding to the second email document, wherein generating the second bloom filter includes setting one or more bits corresponding to and dependent on each hash value in the second set of hash values; and determining whether the first set of hash values forms a smaller subset of the second set of hash values, by performing a bitwise OR operation on the first and second bloom filters.