allowEmpty = PropUtil.getBooleanSystemProperty(
"mail.mime.multipart.allowempty", false);
if (allowEmpty) {
// write out a single empty body part
los.writeln(boundary); // put out boundary
los.writeln(); // put out empty line
} else {
throw new MessagingException("Empty multipart: " + contentType);
}
} else {
for (int i = 0; i < parts.size(); i++) {