When trying to lookup keys to decrypt an email, you receive a "Key not found" error (in reference for the key needed to decrypt the email).
"Key not found" as reported by PGP/Symantec Encryption Desktop w/Outlook Email integration.
Before going further, make sure that a) the user who's key appears to be missing exists and b) that the same user has a key on the server that can be downloaded and accessed by the user who cannot decrypt the message.
Since PGP Universal Server 3.2.1 MP3 was released, there is now an option to allow email for a group policy that wasn't in previous versions. When customers upgrade their Universal Server to 3.2.1 MP3 or higher from an older version, they can run this issue.
You will need to enable email for the group policy of the user who is unable to decrypt messages.
1. Log into the Universal Server web UI as a Super User.