You can do this but you will need an app called smart office 2. You can attach a document and mail it like in my screenshot below. You can use doc,docx, ppt, xls, PDF and probably more but that's all I use.
The app is not free, but worth paying for as it will do the job your looking for.
It's great if your looking to send documents a lot like maybe your CV to employers or documents to colleagues, it should solve your needs.