final int part = ConversionUtil.convertToInt(getPartIndex(), 0);
if (content instanceof Multipart) {
final Multipart mp = (Multipart) content;
if (part >= mp.getCount()) {
throw new StepFailedException("PartIndex too large.", this);
}
final BodyPart bodyPart = mp.getBodyPart(part);
final String disp = bodyPart.getDisposition();
if (Part.ATTACHMENT.equals(disp)) {
return bodyPart.getFileName();
}
throw new StepFailedException("No filename for inline Message Part.", this);
}
return getSimpleMessageFilename((String) content, part);
}