No if they are not on webmail there is a good chance they are gone forever unfortunately. If you have a hard drive crash as opposed to a hard drive failure it's a fairly simple process to recover mail providing the hard drive is still readable. You would be best to speak with your local computer store about that.
Thanks Yeldarb. The hard drive is unreadable so not an option. I am suspicious that Webmail has the exact same number of emails (including trash and spam email) as has Outlook on my new PC but I guess there is nothing I can do now.
The amount of mail left on the server would have been determined by the configuration of your local email program. By default most email clients are set to remove email after a certain amount of days. Unfortunately once deleted from the mail server there is little you can do.