Protection levels
"Letter" level
Sending a message is easy and simple when confidential messages are relayed to the recipients using D-Envelope. At the "Letter" level, the identifier '.s' is added after the recipient's e-mail address (for example, recipient@domain.tld.s). The SMTP-format e-mail message is converted into a format that can be read using a Web browser, the encrypted message is temporarily saved in the system, and the recipient is sent a link at which the message can be read. 
D-Envelope also makes it possible to reply using the encrypted channel, forwarding the response to the sender's normal mailbox.
The link is protected with the Deltagon MessageLockTM technology, so reading the confidential message is restricted. The message can be reopened using cookies or a password. In addition, D-Envelope can verify the IP address, for instance.
"Registered letter" level
Recipient identification offered by Deltagon D-Envelope using SMS authentication ensures that the right person receives the encrypted message at the "letter" level. At the "Registered letter" level, the cell phone number and identifier '.s' are added after the recipient's e-mail address (for example, recipient@domain.tld.040123456.s). The cell phone number can also be saved in the server's database in advance, in which case the sender need not include it in the e-mail message. 
D-Envelope sends the recipient a PIN code as an SMS message when the message is opened. The PIN code is sent when the recipient tries to open a confidential message via Web browser. D-Envelope can send SMS messages to cell phones via an SMS gateway.
