Email client | EPFL Graph Search

An email client, email reader or, more formally, message user agent (MUA) or mail user agent is a computer program used to access and manage a user's email. A web application which provides message management, composition, and reception functions may act as a web email client, and a piece of computer hardware or software whose primary or most visible role is to work as an email client may also use the term. Retrieving messages from a mailbox Like most client programs, an email client is only active when a user runs it. The common arrangement is for an email user (the client) to make an arrangement with a remote Mail Transfer Agent (MTA) server for the receipt and storage of the client's emails. The MTA, using a suitable mail delivery agent (MDA), adds email messages to a client's storage as they arrive. The remote mail storage is referred to as the user's mailbox. The default setting on many Unix systems is for the mail server to store formatted messages in mbox, within th

ClaimChain: Improving the Security and Privacy of In-band Key Distribution for Messaging

Carmela González Troncoso, Bogdan Kulynych, Wouter Lueks

The social demand for email end-to-end encryption is barely supported by mainstream service providers. Autocrypt is a new community -driven open specification for e-mail encryption that attempts to respond to this demand. In Autocrypt the encryption keys are attached directly to messages, and thus the encryption can be implemented by email clients without any collaboration of the providers. The decentralized nature of this in-band key distribution, however, makes it prone to man-in-the-middle attacks and can leak the social graph of users. To address this problem we introduce ClaimChain, a cryptographic construction for privacy-preserving authentication of public keys. Users store claims about their identities and keys, as well as their beliefs about others, in ClaimChains. These chains form authenticated decentralized repositories that enable users to prove the authenticity of both their keys and the keys of their contacts. ClaimChains are encrypted, and therefore protect the stored information, such as keys and contact identities, from prying eyes. At the same time, ClaimChain implements mechanisms to provide strong non-equivocation properties, discouraging malicious actors from distributing conflicting or inauthentic claims. We implemented ClaimChain and we show that it offers reasonable performance, low overhead, and authenticity guarantees.

ACM2018

Enforcing email addresses privacy using tokens

Roman Schlegel, Serge Vaudenay

We propose a system which allows users to monitor how their email addresses are used and how they spread over the Internet. This protects the privacy of the user and can reduce the spam phenomenon. Our solution does not require changes to the email infrastructure, can be set up by the end user on an individual basis and is compatible with any email client as long as emails are centralized on a server (e.g. an IMAP server). Nevertheless, it requires that people use email messaging quite differently

2005

AntispamLab - A Tool for Realistic Evaluation of Email Spam Filters

Luis Hernandez, Jean-Yves Le Boudec, Raphaël Naefen, Slavisa Sarafijanovic

The existing tools for testing spam filters evaluate a filter instance by simply feeding it with a stream of emails, possibly also providing a feedback to the filter about the correctness of the detection. In such a scenario the evaluated filter is disconnected from the network of email servers, filters, and users, which makes the approach inappropriate for testing many of the filters that exploit some of the information about spam bulkiness, users' actions and social relations among the users. Corresponding evaluation results might be wrong, because the information that is normally used by the filter is missing, incomplete or inappropriate. In this paper we present a tool for testing spam filters in a very realistic scenario. Our tool consists of a set of Python scripts for unix/linux environment. The tool takes as inputs the filter to be tested and an affordable set of interconnected machines (e.g., PlanetLab machines, or locally created virtual machines). When started from a central place, the tool uses the provided machines to build a network of real email servers, installs instances of the filter, deploys and runs simulated email users and spammers, and computes the detection results statistic. Email servers are implemented using Postfix, a standard linux email server. Only per-email-server filters are currently supported, whereas per-email-client filters testing would require additional tool development. The size of the created emailing network is constrained only by the number of available PlanetLab or virtual machines. The run time is much shorter then the simulated system time, due to a time scaling mechanism. Testing a new filter is as simple as installing one copy of it in a real emailing network, which unifies the jobs of a new filter development, testing and prototyping. As a usage example, we test the SpamAssassin filter.

2007

AntispamLab - A Tool for Realistic Evaluation of Email Spam Filters

Luis Hernandez, Jean-Yves Le Boudec, Raphaël Naefen, Slavisa Sarafijanovic

2007