Huh? It's fairly common in larger enterprises, everyone I've been working at gave you a template where to fill in the name and then save it in your outlook. To be used with all correspondence, especially external.

Logo, text with address and the usual boring email disclaimer that is half the body that no one reads...

Why "Huh?"? It's about as surprising that many companies don't have explicit email signature policies as it is that some companies do. That is: Not very.