When I left my last job one of my colleagues was a bit upset. Maybe not upset. Testy would be more accurate. After he found out I was leaving in two weeks, he started to subtly accuse me of slacking off in my last weeks. Then he grew more bold, emailing me about "coasting" and emailing responses to work I'd sent him saying that it was mediocre. The nice thing about leaving a job is that you can laugh out loud over the cubicle walls at these emails as the person sending them had no way to get back at you.