Thunderbird is the free email client from Mozilla. With tabbed email and better searching makes this client a good choice to deal with your business emails.
Download the latest release of thunderbird from here.
Once downloaded,install the program as you would with any windows based program.
If you have not used any version of Thunderbird before, the Mail Account Setup window will appear.
It will look similar to the example
If you have used Thunderbird before and started to set it up, then the Mail Account Setup window will not appear.
To make it appear, go to file>>New>Mail Account.
Fill in the blanks of the Mail Account Setup window.
Keep the Remember password checkbox checked so that you will not need to type your password each time you read and send email.
Then click the Continue button.
After you click the Continue button, Thunderbird will determine the correct incoming (IMAP) and outgoing (SMTP) server settings.