TSA won't let ski (trekking) poles through as carry-on baggage; gotta check it.
Outbound, this is not a major problem, although you might get charged for a 2nd checked bag unless it's in a duffle with your pack. The problem comes between the airport and the trailhead. What to do with the mailing tube, since you don't want to carry it on your trek?
Because I'm ending my trek on a Sunday and the PO and UPS Stores will be closed, I can't buy a replacement mailing tube before I have to catch my early morning flight on Monday. Therefore, after claiming my baggage, and before I get on the trail, I'm planning to mail my tube to myself at the hotel where I have reservations on the night before my homeward flight, marked "hold for arrival on Aug 24". Check with your hotel first to be sure they will accomodate this. I'll stuff my unneeded duffel inside the tube and both will be waiting for me when I come off trail. Then I'll reverse the process.
On prior flights, I've always just strapped my Leki's to my pack in the duffle. Being metal, they survived the beating of baggage handlers unscathed. However, I'm not taking any chances with my Lightrek4 carbon fiber poles. One good sideways blow from another suitcase or from being thrown onto a conveyor could spell doom.