How genres emerge and evolve on the Internet has become one of the central questions in studies of computer-mediated communication (CMC). This book addresses the issue of genrefication by giving an in-depth analysis of email hoaxes as a candidate for digital genre status. Email hoaxes are deceptive messages that spread in digital social networks; they are a fascinating object for discourse linguistics as they exemplify a major pragmatic tendency in CMC, namely deceptivity and a lowering of sincerity standards. This study examines formal and functional aspects of email hoaxes and provides ample evidence both from a systematized corpus and in situ data collected online. Besides a structural and microlinguistic analysis, it identifies key issues such as pragmatic duality, narrativity and textual variation and change in email hoaxes. In conclusion, a digital genre model is outlined that bridges both the old/new and the formal/functional gaps and may be applied to many other digital genre ecologies.