Should I send a thank you letter via email?

E-mail is probably acceptable these days. I’d say don’t wait more than two days.

Use the opportunity to stress your interest, add anything (briefly) that you wish you’d said, and express your enthusiasm (without gushing). Enthusiasm is a strong point in your favor.

Yes right away :) Especially for internal interviews

I am an HR person. I don’t receive thank you letters often. In fact, in the past two years I’ve received less than five! So it’s a nice touch. Same day or day after is fine!

The interview was on this past Wednesday….

Send it now.

Don’t make any apology for lagging, though. Just keep it light, sincere, and enthusiastic.

Snail mail (shows more effort) would be better, but email is OK.

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.