In case it helps- here's what I do in an app debug function with a few files, it shouldn't really be any different. I do copy/export them into a user-public folder first before attaching them, and make them world readable.
if (verifyStoragePermissions(c)) { final Intent intent = new Intent(Intent.ACTION_SEND_MULTIPLE); intent.setType("text/plain"); intent.putExtra(Intent.EXTRA_EMAIL, new String[]{"recipient@email.address"}); intent.putExtra(Intent.EXTRA_SUBJECT, "Email Subject"); //build up message ArrayList<Uri> uris = new ArrayList<>(); StringBuilder content = new StringBuilder(); content.append( String.format( c.getString(R.string.message_log_upload_email_body) +"\n\nmodelDesc:%s \n\nmanuf:%s \n\naId: %s,\n\nhIid: %s,\n\nfbId: %s.", Build.MODEL, Build.MANUFACTURER, getSomeVar1(), getSomeVar2(), getSomeVar3()) ); content.append("\n\nMy logged in account id is: ").append(getAccountId(c)).append("."); content.append("\n\nHere's an overview of my attachments:\n"); for (String s : addresses) { File f = new File(s); //noinspection ResultOfMethodCallIgnored f.setReadable(true, false); Uri add = Uri.fromFile(f); //add attachment manifest content.append(String.format(Locale.UK, "|-> %s (%.3f kb)\n", f.getName(), (float) f.length() / 1024)); uris.add(add); } //attach the things intent.putParcelableArrayListExtra(Intent.EXTRA_STREAM, uris); //set content/message intent.putExtra(Intent.EXTRA_TEXT, content.toString()); c.startActivity(intent); }}addresses is a String[] param to that function. I build it up by making the functions I use to export the files return arrays of strings of the addresses of the files they've exported - as I initially store the files in my app's private storage
