Sometimes only a letter will do, but international mail to the US is slow and sometimes luck is involved, too. I'd like to be able to create a letter, add attachments, and have Traveling Mailbox mail it from inside the USA. I'm in Mexico. I could use FedEx or DHL at a cost of $30-$60 for a few sheets of paper. Or Mexican mail which notoriously takes 3 weeks to 6 months, if it ever arrives, so the cheap cost is irrelevant.