The Seagulls won last season's League One title and after a solid start in the Championship sit 10th with 23 points from 16 outings.
Scotland international Mackail-Smith, who joined the club in the summer, feels Gus Poyet's men are good enough to push for another promotion.
"I think we've got a good enough squad," he told Sky Sports. "We showed in the first few games what we're capable of.
"I think in the Championship it's those fine margins. One mistake, or missing one chance and it costs you points.
"We've got a win on Sunday, our first in ten, which was a great relief for everyone and I think we'll push on now."