How long does Marsala wine last after opening and how can I ensure its freshness and quality for as long as possible?

Marsala wine can last for about 1-2 months after opening if stored properly. To maintain its freshness, store the opened bottle in a cool, dark place, seal it tightly with a cork or wine stopper, and refrigerate it if possible. Avoid exposure to air and light, and consider using a wine vacuum pump to remove excess air from the bottle.