Emails using HTML formatting aren't a priori evil, but that are security and privacy risks that come with them, and some people's fancy formatting is really fancy.
More Email Quick Tips
In Mozilla Thunderbird, Netscape and Mozilla, you can reduce both the risk of hurting your computer and the risk of hurting your eyes by reading message in plain old text.
To make Mozilla Thunderbird, Netscape or Mozilla display emails in plain text by default:
- Select View | Message Body As | Plain Text from the menu.

