I take it as just an email formality. It's simply an opening, just like its a formality to respond "thank you for your email".
Also, it's a statement, not a question. So I don't "answer" the statement. If its phrased Asa question, I will answer in some way.
"I don't know! I don't know why I did it, I don't know why I enjoyed it, and I don't know why I'll do it again!" -BART SIMPSON