The only files you can attach to an e-mail while in the Mail app are photos and videos. They can be attached by pressing and holding the press until you get a pop-up box that gives you an option to add one of those files.
If you wish to add a different file (e.g., a text document), you'll have to e-mail it from within the app that use use with the text document. In that case, I suggest you copy the original e-mail text, go to the app that contains the file you wish to send, start a new e-mail from within it and then paste the "old" e-mail info there. That way, you can make it so it looks as if it came from Mail.
Hope this clarifies. Holler back if you need more assistance.
Marilyn
