most commuter rail stations outside Boston

Beverly has 5, Needham 4.
Seems Newton when B&A /NY Central Highland branch was commuter rail and Waltham with long gone B&M’s CM and Bemis branches historically would have had multiple stations in addition to still active Worcester and Fitchburg lines.

Weston has three.
Weymouth has three (if you count East Braintree/Weymouth Landing)

With suburbanization and everyone having cars, railroads didn’t see the need for so many stops. Closing stops also saved the railroads/subsidizing authority money by being able to offload property, not have to regularly replace signage, etc.

As the closer-in suburbs become more developed, we’re seeing talk of more infill stops. JFK, Boston Landing, Lansdowne and the Fairmount Line stops are examples. The restoration of Chelsea in 1985 was the first modern-era infill. It’d been closed since 1958.

Newton 3
Wellesley 3
Brockton 3
Melrose 3