To encrypt a MIME message you must have the recipient’s certificate. It contains the public key required to encrypt the message. To obtain this certificate, ask the parties with whom you want to exchange encrypted messages to send you their X.509 digital certificate in DER file format. For example, you might ask a party to e-mail the .DER file to you or transmit it in a special “certificates only” MIME message, which you can read using the pub.smime:processCertsOnlyData service.

After receiving the certificate, store it in a location (file system, database, or other repository) where it can be retrieved by Integration Server at run time. Once you have access to the recipient’s certificate, you can generate encrypted MIME messages that only the owner of the certificate can read.