Postal mail does have more class and make a better impression, @marinelife, I agree. But on the plus side for e-mail, it’s easy to distribute a message to the interview team and say “Here’s what I received from @cletrans2col.” How many people are going to photocopy or scan a hard-copy letter and send it out internally?
In the large company where I last worked, incoming mail was so rare that people might go for weeks or even months without checking their mail slots.
Perhaps the key is the type of employer. A small firm with a one-person hiring team, a traditional business, an established hotel or other service business with an old-fashioned quality standard: paper letter beautifully presented and sent through the mail. Large corporation, high-tech business, new, young, and modern operation: e-mail is probably the business norm.