The email system is the central battleground against phishing and social engineering attacks, and yet email providers still face key challenges to authenticate incoming emails. As a result, attackers can apply spoofing techniques to impersonate a trusted entity to conduct highly deceptive phishing attacks. In this work, we study email spoofing to answer three key questions: (1) How do email pro...

We introduce a latent activity model for workplace emails, positing that communication at work is purposeful and organized by activities. We pose the problem as probabilistic inference in graphical models that jointly capture the interplay between latent activities and the email contexts they govern, such as the recipients, subject and body. The model parameters are learned using maximum likeli...

Spam is a major problem facing email today, and current solutions are ineffective. This paper presents our progress towards defining and implementing a payment-based email delivery system that solves the problem of spam. We present an extension to the email delivery protocol for specifying and collecting payments, explain its security requirements, and illustrate the use of the Lightweight Curr...

Email encryption techniques have been available for more than a decade, yet none has been widely deployed. The problems of key generation, certification, and distribution have not been pragmatically addressed. We recently proposed a method for implementing a Lightweight Public Key Infrastructure (PKI) for email authentication using recent developments in identitybased cryptography and today’s e...

Summarizing threads of email is different from summarizing other types of written communication as it has an inherent dialog structure. We present initial research which shows that sentence extraction techniques can work for email threads as well, but profit from email-specific features. In addition, the presentation of the summary should take into account the dialogic structure of email commun...

Email is one of the most successful and frequently used computer applications. According to marketing surveys, over 4 billion corporate email messages were exchanged per day in 2001, increasing to a projected 35 billion in 2005. Moreover, 97 percent of workers report using email multiple times per week for a daily average of 49 minutes (Gartner 2001; Levitt 2000; Pitney Bowes 2000). For many pe...

E-mail has become one of the most important communication media for business and private purposes. Large amounts of past e-mail records reside on corporate servers and desktop clients. There is a huge potential for mining this data. E-mail filing and spam filtering are wellestablished e-mail mining tasks. E-mail filing addresses the assignment of incoming e-mails to predefined categories to sup...

The endlessly increasing volume of unsolicited emails (a.k.a. spam) has become more and more of a concern. Its hassles range from a daily loss of time for the end-user, required to keep her mailbox clean, to a financial loss for the ISPs, constantly in need of larger bandwidths and disk space. According to a recent study, MSN and AOL discard together almost five billion of such emails every day...