Applying patch 267 to SMG 10.6.3 causes the view and release links in spam qurantine notification emails to fail to access the qurantine.

In brightmaillog.log:

Aug 16 2017 16:29:33 [http-bio-41443-exec-3] [BrightmailDecrypt] ERROR - javax.crypto.BadPaddingException: Given final block not properly padded

In the control center:

The error will be displayed, "Cannot view the message. The message has either been deleted or released."

Apply SMG 10.6.3 patch 268.

Installing and removing patches for Messaging Gateway

http://www.symantec.com/docs/TECH246891

If you cannot apply patch 268 immediately, you can disable view and release links in the spam quarantine notifications and add a URL to the control center for users to access the quarantine directly.

1. (Spam -> Quarantine Settings -> Notification Format). Uncheck "Include View link" and "Include Release link"
2. Click Edit and add the URL of the control center to the notification template.