Even if you use Outlook, you can still format your email in plaintext.

In Outlook 2000, you can disable HTML formatted emails in the following way:

1) Click on Tools-Options
2) Click on the Mail Format tab in the menu that appears.
3) In the "Message Format" section (top third of the window), click on the pop-up menu and select "Plain Text."
4) Click on "OK"

All of your outgoing mail will be sent in plaintext with default carriage returns set to 76 characters. You can adjust this default by clicking on the "Settings..." button in the "Message format" section of the aforementioned window.