With vines, you need to consider that they're usually fairly vigorous. There's nothing as nice as a mature vine that's doing what you want it to do. But that means you may have to spend some time pruning. If you plan to use vines on a mailbox, make sure you choose ones that won't grow so fast they'll overwhelm it. For a lamp post, you can handle ones that grow taller.
Tendrils are slim, flexible leafless stems that wrap around structures.
Twining vines wind their stems around supports. Clinging vines, like ivy, attach small rootlike holds to walls, trees or other rough-textured surfaces. Most vines grow well in moist, well drained-soil, but there are vines available for all soil and light conditions, according to Clemson Extension Service. Mandevilla, an annual, grows 10 to 15 feet with pink, funnel-shaped flowers and leathery, dark green leaves. Another of his choices for mailboxes is firecracker vine, also known as Manettia.