Me: I can send you the file in a mail or via Dropbox.
Client: My internet is slow. It’s better to send a thumb drive in the mail.
Me: Uh… but then it will take at least 5 days to arrive.
Client: That’s fine.
I did, and he received it a week later.
Client: I want some changes. Should I mail this back to your return address so you can make them?