If you're mailing posters, periodicals or other items that fit into a mailing tube, how the United States Post Office determines its classification depends on weight and shape. You can't send mailing tubes via first-class mail, but most other USPS mailing services do permit them. You can purchase the dual-use priority mail/priority mail express small tube at your local post office. This tube is large enough to ship a golf club or fishing rod.
The least expensive way to send tubed mail is via standard post. Expect your tube sent by standard post to arrive at its destination within two to eight days. Tubes sent by priority mail arrive within one to three days, on average, while those sent priority mail express arrive in one to two days. With the latter, you receive a money-back guarantee if your tube doesn't arrive within that time frame.