I don’t think it is. Perhaps you have a lot more aunts than I do, but everything I can find suggests standard mail had a large minimum (200 pieces?) and prepro

I don’t think it is. Perhaps you have a lot more aunts than I do, but everything I can find suggests standard mail had a large minimum (200 pieces?) and preprocessing requirements. Here’s a page, from the post office itself: “At one time, it was called Third-Class Mail. Today, it's known as Standard Mail. In 2017, it will be called (USPS) Marketing Mail. The U.S. Postal Service has proposed a name change for Standard Mail to better signal to customers that this mail is used primarily to market a product or service.” https://www.uspsoig.gov/blog/names-and-prices-they-are-changinÔÇÖ https://www.uspsoig.gov/blog/names-and-prices-they-are-chang...