Serverside Sign and Crypt E-Mails

[Giovanni Baroni]

We're searching of a solution for a Kolab Server to secure E-Mails.

Automatic and transparent sign an Crypt Messages with GnuPG.
By default the Server has to sign every outgoing E-Mail. Additionally if 
he finds the recipient Public Key ... the server automatically crypt the 
message.
No Client (Outlook) plugins needed!

It would be enough for a single User.

Has anyone done some tests with this, or is it theoretically impossible ?

Thanks
Giovanni Baroni