From time to time someone will walk up to me at work and ask me for somebody's email address. I suppose they could expect me to know assuming that it's someone who works for my company but the queries go far beyond this. This is a common interaction I have:

"Can I get Tom Jerry's email?"
"Who?"
"Tom Jerry. I had it written down but I lost it."
"OK. What account does he work for? I might have it."
"He doesn't work for any of my accounts I just need his email."
"I wouldn't have it unless he was one of our contacts or the head of his agency."
"He doesn't work for an agency."
"Then I don't have it."
"You don't have it?"
"Nope."
"But I need it."

Who Tom Jerry is, I will never know.