Kanhaiya

Email is a very popular way of communicating with others over the Internet. An application that allows users to send, receive, and read email is called an  email client . Red Hat Enterprise Linux includes several email applications, including graphical email clients like  Evolution  and  Thunderbird , and text-based clients like  mutt . Each of the email client applications is designed to suit specific types of users; so, you can choose one with the features that best suits your particular needs. The purpose of this chapter is to demonstrate how to use some of the popular email applications included in Red Hat Enterprise Linux. Since all email clients perform the same basic tasks (send and receive email), you should choose one that is convenient and easy to use. This chapter briefly discusses the following email clients: Evolution Thunderbird Mutt , a text-based email client Before you launch an email client, you need information from your Internet Service Provider

Internet Applications Hey let's write some apps that use the Internet! Those Layers Again So what's an app, or application? Generally, it's something that does something for people, without any concern for how data is actually run between the hosts. In the traditional 5-layer view, anything above TCP is considered  application-level  communication Application Transport (e.g. TCP, UDP) Internet (e.g. IP) Network Interface (e.g. ARP) Physical Transport software just routes packets between applications; it doesn't care what the application data is. Examples of Applications Here are some distributed applications that require well-defined application level protocols Sending and receiving email Browsing information archives Copying files between computers Playing interactive games Most applications not only shield users from transport details, they shield users from protocol "numbers." They define symbolic names for resources and service