POP (short for Post Office Protocol, and also known as POP3) is the name of a protocol which allows you to download e-mail from a server onto your current computer (or any other device, such as a mobile phone, if supported).
POP is one of the main protocols that most people use when sending and receiving e-mails over the internet, esp. if they are using an account that comes with their ISP. It's also very popular as it works when over dial-up or intermittnet connections - you download the e-mail when you want, where you want.
So, how does POP work?
POP works by connecting to the server, logging on using your username and password and then downloading a list of available e-mails. From this list (which doesn't contain any information about the e-mail, just the unique ID of all the e-mails in your account), it can do one of three things:
- Download the headers (these are the informational lines at the top of the e-mail, and describe who sent it, when it was sent, etc.);
- Download the whole e-mail (including the headers); or
- Delete the e-mail.
Most e-mail programs are set to download the whole of the e-mail onto your computer and then delete it when it's been successfully transferred.
When the primary method of connecting to the internet was through a dial-up (and for most people, this is still the case), POP3 was (and still is) an extremely beneficial and flexible way to receive your e-mails. Despite over half of all connections now using broadband or faster, POP3 is still the main protocol for most consumer-orientated accounts.
Drawback Of POP
By using POP, your e-mails are only stored on the server until you download them - unless configured otherwise, your program will delete them from the server once they have been received successfully. Therefore, if you use many different computers or programs, you risk having your e-mail spread our across multiple locations.
However, there is a protocol, supported on all accounts on our servers, called IMAP (or IMAP4) which allows you to view the e-mails which are stored on the server. For more details, please see the following article: