OS X: 10.4, Mail Default Text Encoding

As noted in this Apple reference document, text encoding in 10.4 (Tiger) has changed the default text encoding used for Mail. Instead of the current standard of ISO-2022-JP, the default setting is for UTF. While newer mail applications support this new encoding, there are many mail clients out there who do not and mail written in Japanese will often become garbled.

To change the default encoding in Mail, enter the following in Terminal (single line):

defaults write com.apple.mail NSPreferredMailCharset "ISO-2022-JP"

which will take effect after your next logout/login.