Why aren't email messages automatically decrypted in Outlook 2007?
To encrypt or decrypt email, PGP Desktop uses a messaging proxy. The PGP messaging proxy monitors email to encrypt or decrypt messages when needed. PGP Desktop monitors the email traffic between your email client and your mail server. Depending on the circumstances, PGP Desktop will intercede on your behalf to encrypt, sign, decrypt, or verify messages.
The messaging proxy is also necessary when utilizing email enrollment with a PGP Universal Server. When the email enrollment option is selected for your network, an enrollment email is sent from the PGP Universal Server to the email client and the messaging proxy attempts to decrypt the message to complete the enrollment.
If the messaging proxy is not working the decryption of the message fails.
This can be due to a conflict with the method which PGP Desktop interacts with Outlook 2007 using the MAPI protocol. This can be resolved by editing the Windows Registry and applying a hotfix for Outlook 2007 available from Microsoft by clicking the following link:
Another possible cause for the messaging proxy failure may be caused by Microsoft Exchange components being installed on the system.
If Microsoft Outlook is being used as the email client and Microsoft Exchange components are installed on the system, this may cause the messaging proxy to fail. Therefore the email enrollment message is not decrypted and the enrollment fails. The components may also cause the messaging proxy to fail with stand alone PGP Desktop clients when processing email messages.
This configuration is unsupported by Microsoft and also causes the PGP messaging proxy to fail to encrypt or decrypt email messages. Microsoft Exchange components and Microsoft Outlook should not be installed on the same system per the following Microsoft Support article: