You need to know the support policy for the Symantec Brightmail Outlook Plug-in.
Symantec no longer provides technical support for the OutlookSpamPlug-in. Feature enhancements, other development and software defect fixes for the Symantec Brightmail Outlook Plug-in were stopped as of July 2006. Symantec recommends checking the Knowledge Base for articles on known problems and workarounds for the Outlook Plug-in.
Symantec products, including Symantec Mail Security for SMTP 5 and 8200/8300 Appliances, and third party MTAs, including Microsoft Exchange, have already included built-in Allow/Block list functionality. This renders a need for the Symantec Brightmail Outlook Plug-in less significant.
The effectiveness of end user submissions has been significantly reduced since the first introduction of the Outlook plugin feature due to the evolving nature of spam and the Brightmail product . Missed spam submitted through the Outlook Plugin is typically delayed until well after a spam attack was initiated and new rules have already been implemented .
Symantec has replaced user submitted spam with more dynamic, proactive, and responsive combination of individual Brightmail scanners combined with dedicated spam detection systems maintained by Symantec. As a result, end user submitted spam signatures are typically not useful for protecting against new spam threats.