It has several other useful features as well. You can read more about it by reading this introduction written by the Pine authors or by simply typing pine to run it. Elm Elm is similar to pine. Both offer a menu based interface and features including multiple folders for storing mail. Elm has more features than pine, but is more complex, making it more difficult to learn.
More information is available in the FAQ , the man page, or by simplying typing elm to run it.
MH MH stands for Message Handler. It is a very powerful program, but also very advanced. It offers all the features that Pine and Elm offer, plus many more. The main drawback is that it is very complicated and difficult to learn. It is geared at users who are experienced with Unix.