The RMail encryption service as a default uses Transport Layer Security ( TLS)  for sending and receiving encrypted emails.  

TLS is a secure “tunnel,” protecting the message from the edge of the sender’s network to the edge of the recipient’s network.   When an encrypted message is sent via TLS, it will be decrypted at the server level, and therefore does not require the recipient to input a password to access it.

TLS is enabled by default on our Control Panel for a customer’s account, so messages are always sent securely to RPost, we then use our TLS detection service to determine if the recipient's mail server has TLS enabled.

If TLS is detected, the message is delivered securely all the way to the mail server. The message is decrypted at the mail server and is sent to the recipient's mailbox unencrypted with no password requirement. The message is marked with the RPost banner and is clearly identified as being “transmitted encrypted”.

If TLS is not detected, the messages are sent according to normal encryption settings (i.e. auto password email with senders password or system generated password).

Other encryption options, such as Message Level Encryption as well as Registered™ Encryption and related settings, can be further configured in the Security section of the Advanced Settings Panel.