8. The non-transitory computer-readable medium of claim 5 , wherein the program instructions are executable to generate a similarity indication in response to a user-specified threshold level of matching hash values.
5. A non-transitory computer-readable medium storing program instructions that are computer-executable to: generate a token value for each of a plurality of character sequences of a first email document; generate a remainder value for each of the plurality of character sequences of the first email document by dividing each of the token values by a predetermined integer value; select a first subset of the plurality of character sequences of the first email document, wherein the first subset includes character sequences that have the same remainder values; select a second subset of the plurality of character sequences of the first email document, wherein the second subset includes character sequences that have the same remainder values, and wherein the remainder values of the second subset are different than the remainder values of the first subset generate a first hash value corresponding to the selected first subset of character sequences; generate a second hash value corresponding to the selected second subset of character sequences; and compare the first and second hash values with one or more hash values generated from a second email document.