It reads badly because of the two vowel sounds together ("No es-"); in the OED's citations for especial, all but one (from 1640) precede the word with a consonant sound.
However, there is a more subtle reason.
Especial is archaic. Archaisms have a function in English, but that function is to draw attention to themselves.
With especial, one might write either of
- A special skill is required
- An especial skill is required
but using especial calls attention to it. It must be a really special skill.
When you're saying that no special skill is required, why use a word like especial, with its "really special" sense? It's pointless drawing attention to the speciality of the skill when it's not required.