CertStore certs = CertStore.getInstance("Collection",
new CollectionCertStoreParameters(certList), "BC");
signer.addCertificatesAndCRLs(certs);
/* Sign the message */
MimeMultipart mm = signer.generate(body, "BC");
MimeMessage signedMessage = new MimeMessage(session);
/* Set all original MIME headers in the signed message */
Enumeration headers = body.getAllHeaderLines();
while (headers.hasMoreElements())