Use the Microsoft Open XML File Format Converter for Mac 1.1.5
I remember this converter being finicky with filenaming when I last used it years ago. Something like .DOCX would come up as unrecognized, but .docx would work fine.
Alternatively you could use a Open Source Office competitor like NeoOffice to open them.
I can't open a .docx attachment(which I undertand is created by Word 2008). I use Word 2004 on an iBook, 2005.
Does anyone have a way to open this?