Irish Divorce

The mother-in-law arrives home from the shops to find her son-in-law, Paddy, in a steaming rage and hurriedly packing his suitcase.
“What happened, Paddy?” she asks anxiously. “What happened?”
“I’ll tell you what happened! I sent an e-mail to my wife telling her I was coming home today from my fishing trip. I get home ... and guess what I found? Your daughter, my wife, Mary, naked with Joe Murphy in our marital bed! This is unforgivable, the end of our marriage. I’m done. I’m leaving forever!”
“Ah now, calm down, calm down, Paddy!” says his mother-in-law. “There is something very odd going on here. Mary would never do such a thing! There must be a simple explanation. I’ll go speak to her immediately and find out what happened.”
Moments later, the mother-in-law comes back with a big smile.
“Paddy, I told you there must be a simple explanation... She never got your e-mail!”