Excel 2007 : formatting stripping from spreadsheet when emailed

I have spreadsheets that when I email to another business the formatting is stripped completely from the document. I've tried saving the document in an earlier version of excel and also starting the document new. Both have failed. Does anyone have any other suggestions to try or a solution to the problem. Thank you.
Problem first started when saved original document from 1997-2003version to 2007. I can veiw it with formatting but emailing it, it lost all formatting.