When you receive an encrypted message, its content is not displayed:
You need to activate (unlock) your Private Key first. With the Private Key unlocked, the WebUser Interface module tries to decrypt all encrypted messages with your Private Key. If it succeeds to decrypt the message, the message content is displayed:
When you want to keep the message in your Mailbox, but you want to keep it in the decrypted form, click the Decrypt button. The Server will try to decrypt the encrypted message. If it succeeds, it will store the decrypted message in your Mailbox and will remove the original encrypted message.