As an early adopter of gmail, I was able to get an address with just
surname@gmail.com.
Worked fine for years then started to get emails meant for other people with the same surname who registered on web sites with a space in the email address instead of a full stop, eg firstname
surname@gmail.com instead of firstname.surname
So, I have to apologise to the person in Australia who hasn’t had any success with online dating, the person in New Zealand whose order for timber took a bit longer than expected, and the car executive in South Korea for him not getting his flight confirmation on time.