We describe an investigation into e-mail content mining for author identifi
cation, or authorship attribution, for the purpose of forensic investigatio
n. We focus our discussion on the ability to discriminate between authors f
or the case of both aggregated e-mail topics as well as across different em
ail topics. An extended set of e-mail document features including structura
l characteristics and linguistic patterns were derived and, together with a
Support Vector Machine learning algorithm, were used for mining the e-mail
content. Experiments using a number of e-mail documents generated by diffe
rent authors on a set of topics gave promising results for both aggregated
and multi-topic author categorisation.