Apple Mail text size trick (updated)

Since I was forced to change from Eudora to Apple Mail, I've been irritated about how some emails, particularly from Yahoo accounts, had tiny, tiny, tiny text. Even enlarged to the limit it was smallish, and I had to use time and attention every time.

So I asked my Mail guru, Joe Kissell, author of "Take Control of Apple Mail in Snow Leopard", and he told me from his own book:


If You Prefer Plain Text

To force Mail to display the plain text version of incoming messages initially, you must turn on a hidden preference. First quit Mail. Then open Terminal (in Applications/Utilities) and enter:

defaults write com.apple.mail PreferPlainText -bool TRUE

Quit Terminal and reopen Mail. Messages appear in plain text if available. Use the View>Message submenu to see other formats.

Man, that helped. Buy his books!

Update:
Bruce told me of a Mac control panel called Secrets, which can change this amongst many other things. The best part is that it also has a setting for minimum font size in HTML mails. This is better for me to use, because getting text-only emails removes embedded links and other formatting.
"Secrets" also has many settings for many other apps, Safari for example. I'm looking forward to go over it.
One good thing for example: you can make the Dock a beautiful transparant black instead of the default silver/glass/reflective mode which I don't like at all.