Real estate experts and downtown boosters envision the property being redeveloped into a number of uses. They include a public park that would reduce floodwater impact on the bayous and downtown; an outdoor amphitheater for festivals and performances; and a mixed-use development with housing, a hotel and entertainment venues.
It would be iconic for the city," said Mark Cover, an executive vice president with Houston-based Hines, a real estate firm.
But the process by which the postal service is marketing the site comes with conditions.
The downtown operation at 401 Franklin processes all incoming and outgoing mail for the city of Houston.
Whoever buys the property would have to provide the postal service with another processing, distribution and administrative facility within the boundaries of the city.
The buyer also would have to provide a replacement retail and post office box location near the downtown site where consumers can mail packages and buy stamps.
"This is a project that, at its heart, is about improving efficiencies and having a more attractive retail location for our lobby customers," said regional spokesman Dave Lewin.
The agency's Southwest Area Facilities Service Office, which announced the plan, said it has not put a price tag on the property. And if it doesn't receive an offer that meets its requirements, it will continue to occupy the site indefinitely, Lewin said.
"We've had several unsolicited offers for the property, so we know that there's interest," he said.
And any move to tear down the building could rattle preservationists who say Houston has lost too many of its historical or architecturally significant buildings.
Stephen Fox, a Houston architectural historian and fellow of the Anchorage Foundation of Texas, called the downtown post office a "distinguished work of 1960s modern architecture by an important Houston architecture firm."
That firm, Wilson, Morris, Crain & Anderson, designed or had a hand in downtown skyscrapers, the former Houston Post building on the Southwest Freeway and even the Astrodome. The post office was one of the firm's first big public commissions in Houston, Fox said.
When it was built in 1962, it replaced the Southern Pacific railroad's main passenger station, an art deco building that opened in 1934, according to Fox. It replaced a station that dated back to 1886.