Your password is the main barrier from the hacker attack. It needs to consist of at least eight or ten characters of different types, i.e. from large and small letters, numbers and other characters. Also, it should not be something to do with your life, otherwise the task of the hacker is very simplified.
Never respond to emails asking for you to provide your password as this is a very popular method of extraction password. It is especially dangerous for those who uses the same or slightly different from each other passwords for different services.
Leaving the mail, be sure to press the "Exit" button, and then the hacker cannot steal the Cookie, with which it can penetrate in your Inbox.
Use to create a virtual mailbox only known and verified postal service, as they are regularly updating their services and consequently, improve the protection. The best services are gmail.com, mail.yandex.ru, mail.ru and yahoo.com.
Always, before you download some kind of offer in the letter file, or to follow a link, be sure to verify that it is you exactly need. No one can guarantee you complete protection.