How do you remove the annoying envelope icon from a downloaded file on an iphone?

I have music files I have to sometimes download from my emails which is nothing new. Sometimes it has a strange and annoying envelope icon next to it because sometimes it's from an email I had to send myself to merely download it. How do I go about removing this icon from the files in question from my iphone? I've seen similar questions about this but normally only relating to an ipad or usually just a computer which i don't have. Can this be done from the phone itself? Its highly distracting and a bit of a nuisance. Any help would be greatly appreciated.