I had backed up my Outlook.pst file before restoring it after formatting my
hard drive. Now, all my emails download from Yahoo servers although they are
already in my outlook inbox. Is there a way Outlook can realise the mail
that
had already been downloaded in the past?
No. Instead there are two other approaches you can take. One is to log into
your Yahoo mailbox using a web browser, create a new folder on the server, and
move all of the items in the Inbox which you have already received to that new
folder. If they're not in Inbox, Outlook can't see them and won't think
they're new.
A second is to create a new PST in your mail profile using the Mail applet in
Control Panel (using the Data Files button), make it the delivery location
with the E-mail Accounts or Data Files button, depending on your version of
Outlook (which you decided to keep secret), start Outlook, allowing it to
download all your old mail, then close Outlook and use the Mail applet to
remove the extra PST from the profile, making the original PST the delivery
location again.
