So I was saving MS office documents to my mac, and had to email an assignment to my teacher whom recieved it and couldn't open it because I then noticed I sent it and it had no file extension so I added .docx and sent it to her. But I was playing around with the same file and remove the .docx extension and sent it to myself and this time it did have the file extension on my Windows computer Also I have finder to not show file extensions and they still do, I'm a bit confused about all this. I just want my word files to save as .docx but seeing extensions annoys me so I want them to stay hidden. So right now in MS Office I have to save as filename.docx, find the file in finder and remove the .docx manually. There has to be a way around this, right?