About Money: The US funded many projects & countries with money, equipment, supplies, & resources, to try to help rebuild/ build up their countries, while trying to stop communism from spreading it's control over those same countries. The USSR also tried to gain control of territories by taking them over militarily, or sending resources & setting up Communist governments that supported the USSR. This usually costed a lot of money, & sometimes put strain to their economy (especially for the USSR's)
About Mail: The US used censors during the Cold War, and tried to find communist sympathizers and communist spies that were located inside the US. They would read people's mails to find out if they were pro-communist, and take decisive action depending on what it was.
. About the Military: Both sides supplied military & logistical needs to their allies, as seen in the Korean, Vietnam, Bay of Pigs Invasion, etc wars. Take for example the Korean war. The US & the NATO sent support to help stem off the Communist onslaught, & today they are still split. (this is technically a success, because this was their first objective anyways). Another example is the Vietnam War. With the knowledge of terrain, support from China & the USSR, the Viet Cong was able to defeat the US, as the US soldiers were unfamiliar with the area, and the support for the war was growing cold. As seen in the Bay of Pigs Invasion, the US & USSR did not intervene directly. The USSR trained & supplied Fidel Castro, while the US used the CIA to train the exiled people to try to topple Castro's government. This failed, & was a win for the USSR.