Last month, Open-Xchange has released OX Guard v2.0.0.
One of the major changes is that OX Guard now is using PGP. You are free to use your own PGP key pairs, or simply let OX Guard create some for you. You can im- and export keys, but you don’t need to care about PGP and key management at all.
OX Guard is really simple to use – watch this video to get some easy explanations about the encryption and decryption process.