E-mail scanner freezes system

Dear Symantec,

 

on multiple WindowsXP systems we have, the Norton AV e-mail scanner persistently freezes or significantly slows the rest of the platform until scanning is completed. This occurs mostly when we are sending attachments. This prevents us using Windows Explorer, launching programs etc. It is clear that the Norton outgoing scanner is taking most of the system resources, leaving us with no bandwidth for other activities.  This has been the case for Norton Internet 2008 and Norton Internet 2009 which we have just installed. Is there some way to restrain this rather aberrant behaviour ?

 

Regards,

Andrew