MIME type Memo
.doc application/msword
.xls application/vnd.ms-excel
.ppt application/vnd.ms-powerpoint
.docx application/vnd.openxmlformats-officedocument.wordprocessingml.document
.xlsx application/vnd.openxmlformats-officedocument.spreadsheetml.sheet
.pptx application/vnd.openxmlformats-officedocument.presentationml.presentation