Recover email data deleted on WIN98

Friends have a older PC still running win98 as that is all they need… use it for email and such…they use MS OE7 for mail…they accidentally deleted some mail, then have their settings to deleted all trash.. How can they get to the deleted emails.. Not sure about 98 and getting data back.. or how to scan their HD for it..and do not want to mess up what they have on HD.. will do so over phone..thoughts