An update to the ever-popular Publicity Basics posting -
The next time your organization is thinking of sending out a mass mailing, check what it looks like on a few popular mobile phones: iPhone, the Android model of your choice (in a browser AND the native Gmail client), Blackberry, etc.
If the user has to scroll all over the place to read your mail, change the format. This happens most commonly on my Android phone with HTML email that uses fixed-width columns for formatting.
If you're sending out Word documents or PDFs, your important news won't necessarily get read on a mobile phone. Most mobile phones have limited or no support for those formats.
Once again: plain text and rich text are the safest formats for emailing publicity info. Prettiness is less important than getting read. Don't make people open another application to read your press release; don't make them click a link to find vital information; don't make them scroll.
I'm going to add one more good reason for this: plain and rich text are friendly formats for people who use screen readers.