Outlook | why do we treat email differently to snail mail

Someone posed this question to me the other day 'why is it we treat email so radically differently to how we treat snail mail?'

What did they mean, well let's have a look. If I got up in the morning and went down to my letterbox at the front of my house, opened it up and took out my mail. Then while standing in front of my mailbox opened up my mail and read it, then when I had finished reading it out it back in the envelope and put them back in the mailbox or one of the 15 other mailboxes nailed to my fence that people woul think I was insane. And probably rightly so.

However don't we do this every single day with our email. Don't we deal with it in exactly the same place that it comes in.

My question to everyone then is why do we do this with email when we are not willing to do it with paper mail.