Post Office Protocol Version 4.POP 4 is a specification for a few extensions to the POP 3 internet email protocol that gives much greater flexibility to email client programs without adding a heavy burden to the POP server. Why POP 4? POP 3 is based on the principal of providing simple functionality on the server and putting all of the intelligence on the client. This works well enough because most of the world is using POP 3 a
