Mail will be held in the person's electronic inbox until they decide to read it. If a hostnode is down between your computer and the destination computer, mail will be stored at the last computer that was up and will be forwarded on when the path is up again.
Mail is the most commonly used method of communicating on wide are networks.
There are several e-mail packages available on the Unix system. Pine will be used as the e-mail package here. It is available on all of GSU's general-access UNIX computer panther. Pine was designed for novice computer users. To achieve this, features included were limited and carefully selected.