Here's another option, a plastic sleeve, either over the whole thing or just over the surface where the pole tends to decay:
Plastic Post Covers - Plasti-Sleeve - The original in post frame protection!
"Post Protector" is another brand, I think they have drain channels along the sides so that even if the section gets wet the water has a way to drain away.
Plastic Post Covers - Plasti-Sleeve - The original in post frame protection!
"Post Protector" is another brand, I think they have drain channels along the sides so that even if the section gets wet the water has a way to drain away.