When I send someone an OpenOffice document as an attachment, they cannot open it. Why not?
This may be because you sent them a file in the OpenOffice file format and Microsoft Office does not (yet) support this format. Unfortunately most people only recognize MSOffice files as the only way to exchange files. To save your document as MSOffice files use the OpenOffice menu “File” => “Save As…” and, from the lower drop-down box select the version of Word or Excel you want to save it in. Be aware that older versions of Word does not always read newer Word documents, but in general the best format to pick is Word97/2000/XP.