How do I convert a Microsoft PPT file to upload as a message on my iphone

Where does the PPT file originate? Mac, PC, iPhone

Does the recipient need the file to be PPT format?

If there are no restrictions on the format of the file, I would convert it to Keynote and that can be sent by message simply by tapping the Share button in Keynote. When sent by message, you also have the option to send a copy or collaborate by allowing the person make changes. If the PPT file is on a computer, just email it to your device as an attachment. When opened on the iPhone, it will open Keynote and convert it.