The American delegation was led by Lea Emerson, executive director for international postal affairs at the U.S. Postal Service, and included State Department officials. They met with Cuban counterparts, including Johana Tablada, deputy director of the Foreign Ministry's U.S. affairs division.
A State Department communique called the talks "fruitful" and said delegates would tour Cuban mail facilities Tuesday.
"The re-establishment of direct transportation of mail between the United States and Cuba is consistent with our goal of promoting the free flow of information to, from and within Cuba," it said.
Cuba said in a statement that the discussions were "respectful" and both sides agreed to meet again in the coming months.
Mail service between the two countries was canceled in 1963. Currently, letters mailed from the United States to Cuba and vice versa take circuitous paths through third countries even though just 90 miles of sea separates the island nation from Florida.
Monday's meeting follows similar negotiations in Washington in June. Cuba and the United States also held migration discussions in July.
Both sets of talks had been on hold since 2009, when USAID development subcontractor Alan Gross was caught bringing restricted communications equipment into Cuba.
He was sentenced to 15 years in prison under a statute governing crimes against the state, although he argues that he never intended to harm Cuba and was only setting up Internet networks for island Jewish groups.
Resumption of talks this year was seen as a positive sign for relations, even if the two sides are still far apart on many issues such as Gross' detention, the imprisonment of five Cuban agents in the United States and Washington's 51-year-old economic embargo against Cuba.
With no formal diplomatic relations between Havana and Washington, such discussions have in the past served as a pretext to talk about other issues.
In 2009, a senior State Department stayed in Havana nearly a week after mail talks and met privately with Cuba's deputy foreign minister in the highest-level contact the two governments had had in decades.
Peter Orsi on Twitter: www.twitter.com/Peter—Orsi