Valid Certificate Required in Outlook 2007

PKI Tutorials - Herong's Tutorial Examples - Version 2.04, by Dr. Herong Yang

PKI Tutorials - Herong's Tutorial Examples

∟Valid Certificate Required in Outlook 2007

This section describes how to request digital signature and encryption when sending an outgoing email message in MS Office Outlook 2007. An invalid certificate error message shows up if you don't have any personal certificate that matches your email address and is issued from a trusted root CA.

Now let's try to send a test email message with encryption and digital signature.

1. Run Outlook 2007 and click "New" to create a new test email message.

2. Click the Digital Signature icon and the Encrypt icon in the "Options" menu group under the "Message" menu.

3. Click the "Send" button. Outlook displays an error message: "Microsoft Office Outlook cannot sign or encrypt this message because your certificate is not valid." See the picture below:
Outlook 2007 Invalid Certificate Error

Looks like I need good certificate that matches my email address and signed by a trusted root CA to be able to use Outlook S/MIME encryption and digital signature functions.

Last update: 2011.

Table of Contents

About This Book

Introduction of PKI (Public Key Infrastructure)

Introduction of HTTPS (Hypertext Transfer Protocol Secure)

Using HTTPS with IE (Internet Explorer) 10

Using HTTPS with Chrome 40

Using HTTPS with Firefox 35

Perl Scripts Communicating with HTTPS Servers

PHP Scripts Communicating with HTTPS Servers

Java Programs Communicating with HTTPS Servers

Certificate Stores and Certificate Console