Again as I said earlier you need not be a rocket scientist to hack emails using these methods. The success of the hacks depends greatly on the stupidity level of the victim. What does the attacker do is to send a trojan to the victim using any file sharing program, or yahoo messenger or any other messenger, even a website. The attacker usually binds the trojan with any mp3 file or sometimes jpeg so that it would look harmless.
When the victim downloads the file, the server part of the trojan gets installed on the victim’s computer and the attacker is notified the IP of the victim and the port number on which the trojan is running. The client part of the trojan runs on the attacker’s machine which he uses to connect to the server running on the victim’s PC. And, boom, the attacker gets access to the PC of victim.
One commonly used software used for this hack is PRORAT. You can get it from http://prorat.net , some anti-virus programs detects it as a trojan so remember switching off your av. You can get the tutorial on the usage of prorat from its website.
Now, similar is the process for installing a keylogger which detects all the keystrokes of the victim. Commonly used keylogger is Ardamax which is available on many sites like rapidshare, You can even get the crack for the trial version. It has got a lot of features like notifying the keystrokes of the remote victim through ftp.
Just use this article for your knowledge and for your defence.