Autosearch for certifikates

Hello,

we are testing the mail cipher gateway.

Beside, that the gateway can auto add s/mime certifikates from incoming
mails, is there a way, that the gateway can automaticly search for s/mime or
pgp keys on various keyservers?

Does anybody know an open source certifikate server, which can do the
lookups fort he gateway?

Regards,

Ralf Kirmis