This master thesis looks at how electronic mail (e-mail) should be assessed when used as evidence. There are two parts, a theoretical part that focus on the technical properties of e-mail, and a practical part which includes a test of selected e-mail clients. The practical part was done to test the robustness of e-mail clients against manipulation.
The main focus is on the properties of e-mail messages, and how they can be manipulated in various ways. By using a technical approach it is possible to analyze how strong an e-mail is as evidence. Closely related to the technical properties of e-mail, is the actors involved from the e-mail is sent to it is received. An overview of actors, and their functions in the process of transmitting e-mail, will also be presented.
The most interesting finding of the testing was how easily it is to manipulate e-mail messages in Thunderbird, and how this weakness could be used to compromise e-mail providers through the protocols POP, IMAP and SMTP.