Lost Mail (mail1.2.5, Osx 10.2.80, Imac 800mhz 17inch)

John H

After moving an unwanted email from my inbox, I hit the option to Erase deleted messages . I then got a message saying there were problems compacting my inbox, due to lack of space. The result was the loss of everything in my primary Mailboix -Three years of carefully emails that I had regarded as keepers.

Is it possible to get them back? Space should not have been a problem, with over 40 gig of free sopace on my HD.