I've received a mail with an RTF attachment, and I'm unable to read it: "no application installed for this file".

Furthermore, I can import and read and modify a MS Word document, but when I save it and send to a email recipient, he can't see it with MS Office suite, neither with Wordpad, but just with OpenOffice suite.

What can I do with this 2 kind of files?

Any help will be appreciated... thank you!