When you try to read or decrypt an encrypted email in the browser using Zero Download, the following error message shows:
Server Error in '/' Application
Description: An application error occurred on the server. The current custom error settings for this application prevent the details of the application error from being viewed remotely (for security reasons). It could, however, be viewed by browsers running on the local server machine.
Details: To enable the details of this specific error message to be viewable on remote machines, please create a customErrors> tag within a "web.config" configuration file located in the root directory of the current web application. This customErrors> tag should then have its "mode" attribute set to "Off".
Encrypted emails always come with the encrypted_message.htm attachment file. Aside from the HTML code and meta-tags, this file also contains the message payload in encryted data sections.
The above error occurs when the HTML code and/or meta-tags are modified by content filters that scan your emails before arriving in your mailbox.
To resolve the issue, the administrator should set exclusions.