So what are some occasions other than weddings in which you should send a thank you card? To the host of party that was thrown in your honor, for baby shower gifts, for gifts sent by mail, after being hosted as a houseguest (who is not a close friend or relative) or for congratulatory or sympathy gifts, are just a few. When someone spends both time and money to select and send something special for you, there’s really no excuse for not spending five minutes writing that note and 49 cents on that stamp to acknowledge it. You will thank yourself you did.