How to get a two year old deleted dbx email?

I need to get ONE old deleted email from June of 2006 was in OE OR thunderbird..they do NOT remember which..but think it “Was with the MS email”..
They do NOT want to buy SW for only one email retrieve as they will toss the HD after they get email off.. system is Xp and very firm on buying SW.. So any SW out there or any way to find without it… Noted some freeware..but not sure if any of it works. Suspect someone out here knows of something. Thanks..
NO I will not buy their SW for them. did that to many times already.