Great Customer Service

How is it so many people don't seem to know their own email address? I fairly regularly receive emails that are meant for other people - usually it's because they have the same name as me, and presumably use the same email provider. I generally just delete them (although when I received a booking confirmation for a hotel in Paris I was tempted to turn up!). They're usually just one-off occurrences, however recently I've been receiving a number of UPS dispatch information emails addressed to a man named Frederick. It became clear this chap had used my email address in his customer record, and was quite a prolific customer! So I notified the customer service email address of the situation, and received this reply very quickly. I've also received no further emails - excellent customer service :)