private static BodyPart getBodyPartFromDatasource(final AttachmentResource attachmentResource, final String dispositionType)
			throws MessagingException {
		final BodyPart attachmentPart = new MimeBodyPart();
		// setting headers isn't working nicely using the javax mail API, so let's do that manually
		final String fileName = determineResourceName(attachmentResource, dispositionType, false, false);
		final String contentID = determineResourceName(attachmentResource, dispositionType, true, true);
		attachmentPart.setDataHandler(new DataHandler(new NamedDataSource(fileName, attachmentResource.getDataSource())));
		attachmentPart.setFileName(fileName);
		final String contentType = attachmentResource.getDataSource().getContentType();
		ParameterList pl = new ParameterList();
		pl.set("filename", fileName);
		pl.set("name", fileName);
		attachmentPart.setHeader("Content-Type", contentType + pl);
		attachmentPart.setHeader("Content-ID", format("<%s>", contentID));

		attachmentPart.setHeader("Content-Description", determineAttachmentDescription(attachmentResource));
		if (!valueNullOrEmpty(attachmentResource.getContentTransferEncoding())) {
			attachmentPart.setHeader("Content-Transfer-Encoding", attachmentResource.getContentTransferEncoding().getEncoder());
		}
		attachmentPart.setDisposition(dispositionType);
		return attachmentPart;
	}

	/**
	 * Determines the right resource name and optionally attaches the correct extension to the name. The result is mime encoded.
	 */
	static String determineResourceName(final AttachmentResource attachmentResource, String dispositionType, final boolean encodeResourceName, final boolean isContentID) {
		final String datasourceName = attachmentResource.getDataSource().getName();

		String resourceName;

		if (!valueNullOrEmpty(attachmentResource.getName())) {
			resourceName = attachmentResource.getName();
		} else if (!valueNullOrEmpty(datasourceName)) {
			resourceName = datasourceName;
		} else {
			resourceName = "resource" + UUID.randomUUID();
		}

		// if ATTACHMENT, then add UUID to the name to prevent attachments with the same name to reference the same attachment content
		if (isContentID && dispositionType.equals(Part.ATTACHMENT)) {
			resourceName +=  "@" + UUID.randomUUID();
		}

		// if there is no extension on the name, but there is on the datasource name, then add it to the name
		if (!valueNullOrEmpty(datasourceName) && dispositionType.equals(Part.ATTACHMENT)) {
			resourceName = possiblyAddExtension(datasourceName, resourceName);
		}
		return encodeResourceName ? MiscUtil.encodeText(resourceName) : resourceName;
	}