Google Message Encryption Administration Guide - Manual (Page 29)

30 Postini Encryption Services Administration Guide
Set Up Portal Delivery
To set up Portal Delivery, you’ll work with an account representative to enable the
service. If you will be setting up a Custom Portal, additional design time may be
required.
Prerequisites
Using Message Encryption, Portal Delivery requires that you route your mail
through Outbound Services. For instructions on how to do this, see the Outbound
Services Configuration Guide.
You will also need to enable Transport Layer Security (TLS) on your mail server.
Setting up TLS on your server ensures that your confidential email is secure
throughout transmission. For information on implementing TLS on your mail
server, check your mail server documentation. If you are using multiple servers,
enable TLS on each server that routes mail to the email protection service.
Transport-Level Security (TLS) is an industry standard for secure email. Setting
up TLS usually involves installing a certificate on your mail server. You can use a
purchased certificate, or a self-signed certificate. For information about setting up
TLS, see the documentation for your mail server.
Also, you will need to enable Transport Level Security in the Administration
Console. For steps on setting up TLS in the Administration Console, see below.