One of my colleagues did a lot of work in Japan in a very niche industry.

They lost their shit one day because he replied to an email without the formal salutations…like rather than Dear Honorable Hiro San, We thank you for your data transfer, and will begin the process of review; He wrote something like Hey Hiro, got your files, and will investigate. Thanks.

It was a big kerfuffle with managers involved on how he could be so rude and disrespectful.