Smiting with a +1 flaming sword in 3.5 would only deal 1d6 fire with the rest being magic slashing damage.The type of damage comes from the weapon use. If its a flaming sword, then its fire damage.
Which is weird isn't it?Using Smite Evil does not make it qualify for "Good" to bypass DR in D&D 3.x.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.