Remember you can click on any of the screen shots to view a larger version.
Download and install Thunderbird from: https://www.mozilla.org/en-US/thunderbird/
At the System Integration screen you should check the E-Mail box IF you want Thunderbird as your default Email program.
Make sure you un-check the "Always perform this check when starting Thunderbird" box.
Then click the "Set as Default" button to continue.
The bizarre Welcome dialog just needs to be skipped. Click "Ship this and use my existing email" button at the bottom of the dialog to move on.
Thunderbird has a very easy setup as you only have to enter a few things and everything else is taken care of for you.
Enter your name as you wish it to be shown on your Emails, your Email address and your Password.
You can optionally check the box to have Thunderbird remember your password or else it will ask each time you use the program.
Click Continue and Thunderbird will try to validate your settings.
If everything was entered properly your screen should show the OWT server settings at this point as in the graphic.
You now select between IMAP and POP3. IMAP will ALWAYS store the Email on the OWT mail server whereas POP3 will retrieve the Email and store it on your computer. Note that the default settings will actually leave 14 days of Email on the OWT server so that you can still view current Email with a mobile device etc.
We suggest using POP3 for desktiop computers and certainly for your primary computer but check the appropriate radio button and then click "Done".
At this point your Email should now work but if you need to make changes click on the tools grip in the upper right corner and select either Options for Account Settings.
You can tweak your settings extensively if you wish. We feel the default settings are pretty good overall but Thunderbird is easy to customize.