I have been using Outlook and Outlook Express to access my mails. Since I use the remember passwords option, I forgot my password for a very important email account. There was no option to reset the password, so this is the freeware I used to find it.
RockXP is a tool that allows you to retrieve lost email passwords and change Windows CD keys. There is no installation just run the file, choose what you need to find and hit scan. There are many options in RockXP that lets you find a lot of information. I will not write about it here, read the authors page for more information.
Disclaimer :- I am not responsible for what you do with this software and any consequences. Your use of the software is at your sole risk.