[otrs] Use otrs together with encryption

Hi folks! is there any possibility to integrate encryption in otrs? we need to decrypt incoming mails before adding them to otrs and encrypt outgoing eMails before they are sent. this may be a eMailserver task but in my opinion the encryption/decryption should be done as late as possible, that is only by the recipient (which is the otrs system in this case). Does any kind of plugin etc. exist which does the decryption (by using gnupg???) or / and encryption? Or has someone a script to automatically decrypt incoming eMails before they are passed to PostMaster.pl? any help / comment is very welcome. Sven