Mozilla Thunderbird is one of the most popular postal customers. Such a program will work in any place. The application protects against spam and pop-up advertisements. Additionally, it reduces the risk of virus attacks. Thunderbird opens messages in separate cards, which enables quick switching between them. It works on the basis of an encrypted Internet connection, which encrypts your emails. The program also supports RSS downloads. The program is supported by simple and intuitive operation and reliability of work.