If you are familiar with programming languages like C++, Java, Perl, Python, Ruby, HTML, or XML-Script then you have certainly come across POP. In computer programming, the Post Office Protocol (POP) is an email client-side standard protocol used to retrieve e-mails from a specified mail server. It can be implemented on top of an existing Internet service (ISP) or on its own. The original purpose of POP was to provide an efficient way for mail recipients to unsubscribe from unwanted electronic mails. POP version 3 is now the latest version in widespread use.
The most commonly used version of POP protocol is version 3.0, which was released in September, 1997. This protocol version is capable of transmitting over short and medium distances and supports authentication using either MAC (Message Authentication Code) IP address, Kerboard message, or any other authenticated request-key. The sender does not need to specify the header or the subject field for his unsolicited message to be delivered over different ports.
Pop objects can contain a large number of non-textual data, including numeric values, numeric sequences, references to tables or formatted data, and application icons. Some messages include both text and icon references. These types of messages are commonly used in interactive applications such as spreadsheets and word processing applications. Pop objects can also be used with the standard POP message to carry out additional functions, such as checking and retrieving e-mail addresses or performing multiple-way Internet connectivity.