Working with latest version of MS office (Word, Excel, Powerpoint) is very easy because kin new version of MS office Microsoft added so many new feature with a new easy to use interface. But there is a generally problem with New version of MS office (2007 and 2010), that they use different file extension for files like .docx for MS Word file instead of .doc as in old versions. and .xlsx for MS Excel instead of .xls.
Now whenever we send an attachment of a file saved in new version and the receipt email user have over version of MS Office, he cannot open that file. There are two options to solve this issue
One is, you save as that file again with 97-2003 format of word or Excel using File > Save as > save as 97-2003 ……. and mail the file again.
2nd, You can Open as a Google Document and Using Google Docs options , you can download again in desired format of MS Office. (Go to File > Download As and select your desired format)
Options in email to Open as a Google Doc
This is very useful way when u dont have latest version of MS office with you and you need to urgently convert a file to lower version.