I was actually reasonably impressed with the system; they don't put nearby words near each other, so if you have a typo it becomes pretty obvious to anything but the most braindead delivery system.
So if what you're writing on the envelope is
Bob Smith
reporter.smoked.received
France
it becomes trivial to correct that to reporter.smoker.received, unlike when you write "124 Main Street" instead of "123 Main Street".
To what3words' credit, when I typed reporter.smoker.received into the map tool, it did suggest the correct location in its list of similar locations. https://imgur.com/G2ChrxA.png
So if what you're writing on the envelope is
it becomes trivial to correct that to reporter.smoker.received, unlike when you write "124 Main Street" instead of "123 Main Street".