user set delivery in PST and start receiving multiple email from one user
user also set multiple email account in outlook
is this issue is related to virus???

issue is resolved when we delete everything in outlook and reconfigure the  email in outlook which set the delivery in mail box and create new PST working fine.
but after few days it start again the same issue.

clients information
SEP MR6a
Windows XP 32bit SP3 with latest patches
office 2007
on exchange we have Symantec Mail Security 6.5 as well.

need your people support thanks in advance.