What is POP3?




We’ve seen how SMTP is used in the process of sending emails, but how does this process work in reverse? What processes are available for receiving emails from the server to the client. One such method for receiving emails is known as POP, or Post Office Protocol.




 Now, notice that because it is a protocol, this means that it serves as a means of guidelines for communication between clients and servers along networked computers. So, what is POP, exactly, and how is it used? As noted, POP is only one of the methods for receiving incoming email from a server to a client.

So, let’s start off with one question: what is POP? Though we’ve defined it in general terms, let’s look at it in a more specific manner so that we can understand what it really is. Without taking a closer look at the specifics behind this protocol, it’s difficult to understand how it works and influences us in our daily lives.

 Though we’ve all probably encountered POP at some point in our lives before, it can be very difficult describing what POP is and how it can be used by a client in order to receive email from a server.

POP3 is supported by nearly all email clients and servers. POP was designed as a means of downloading and deleting messages, all on a remote email server. If this sounds confusing, don’t worry. It kind of is! And, that’s okay. What all this means is simply this: POP3 allows one to download email from the server to the local client computer on a specific email server.

However, one of the drawbacks of POP is that it will have the email deleted from the email server. This means that once the email has been downloaded to a specific client’s computer, it cannot be accessed again from the original email server. Furthermore, they may only be accessed on the computer on which the emails were downloaded.

 In this way, POP can be very limiting in that you cannot access downloaded emails from multiple devices and must instead rely upon being in the same location as the client onto which you downloaded the emails.




So, for instance, if the emails were downloaded to your laptop, you wouldn’t be able to access the emails again later from your phone or work computer. This may be seen as a drawback, as it highlights the one-way nature of POPs transfers.