“People don’t know; they go in there and think they’re dealing with postal employees,” said Darla Kilgannon, who retired after 34 years with the Postal Service and remains an APWU member.

Over the past two months, Lysaght and others have taken their cause to more than a dozen Bay Area Staples stores to warn passers-by not only about mail security but financial security, saying the outsourcing of postal services threatens the future of living-wage jobs with health benefits.

“This erosion affects everyone,” said Lysaght. “If someone makes $50,000 a year instead of $18,000, they can afford to patronize this business” — he glanced across the driveway toward the Staples — “buy a car, perhaps own a home.”

Carrie McElwee, spokeswoman for Staples Inc., referred questions about the partnership and its future to the Postal Service. “As a matter of policy, we don’t provide details on our pilot programs or on our agreements with vendors,” she wrote in an email.

Augustine Ruiz, a spokesman for the Postal Service, said the purpose of the pilot program at 82 Staples stores was to “collect data and feedback to enable the Postal Service to validate operational and financial assumptions to determine if expansion is suitable.