Messages with the "Deliver to Spam Quarantine" action are not appearing in the Spam Quarantine but instead remain queued in the Messaging Gateway delivery queue with a "421 Closing Connection" message as the last error.

Message Queue:

"421 Closing Connection"

BrightmailLog.log:

Mar 18 2013 19:44:55 [SmtpWorker-12] ERROR - Cannot create a spam message in the database. 
com.symantec.smg.controlcenter.internal.dataaccess.DataAccessException: An
unexpected database error has occurred. Please contact your system 
administrator. ; nested exception is: 
    com.mysql.jdbc.exceptions.MySQLIntegrityConstraintViolationException: 
Column 'from_addr_email' cannot be null

 This is caused by a malformed From header in the message which is preventing the message from being inserted into the Spam Quarantine database.

This is addressed with the SMG 10.5 release.