IN THIS CHAPTER
Learning the ins and outs of email security
Encrypting email logins and message transfers
Securely checking email over the web
Encrypting messages end to end and using digital signatures
Reducing the influx of junk mail
Discovering where email came from
Encrypting instant messaging sessions
Preventing others from hearing audio transmitted over the Internet
Your Mac enables you to communicate over the Internet in many different ways. When it comes to one-on-one conversations with other people (or companies), the most common modes of communication are email, instant messaging (along with its audio and video chat variants), and voice over IP (VoIP), which can extend audio chats to people using conventional telephones. In all these cases, your Mac is the conduit through which you may send or receive highly personal or confidential information. This chapter covers ways of preventing that information from being intercepted in transit (and, in the case of email, being read while stored on a server somewhere).
The important thing to keep in mind about all these forms of communication is that even though you may think you're talking (or typing) directly to another person, the data doesn't go from one computer straight to another; it travels through numerous routers, gateways, and servers — each one potentially vulnerable to snooping, sniffing, or other unwanted attention. Because you can't control every portion of the network ...