Hi
In previous versions of Word you used to be able to embed styles and formatting so documents could travel freely between users. However I am unable to locate that functionality in Word 2010.
You may or may not be aware that when you create a document using a given template (usually Normal.dot) and that document is opened on a different machine the target machine will use it's own version of the Normal.dot template settings.
Initially I would suggest saving your document as a template and sending the template, that way the styles and formatting should not alter.
I am sure the functionality to embed styles and formatting is still in Word 2010 but at the moment I cant locate it.
The other option which if feasible, will help. If all your users are set to use a template that is stored on a network. So as long as the correct styles and formatting are stored in the networked ntemplate you will not experience the problem you currently have.
Hope this helps.
Good luck.
Tony