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Email, Acronyms, and You: The Different Ways that Email Gets Delivered

Email – it’s already starting to feel dated…

it’s easy to send and receive emails every day without giving any thought to what’s going on behind the scenes. While it’s convenient to assume technology just works, there are in fact three standard methods used to deliver email. Furthermore, the method you use for sending and receiving mail can have distinct pros and cons when it comes to office productivity.


When someone sends you a message through an email client such as Microsoft Outlook or Mac Mail, their computer uses a computer language called Simple Mail Transport Protocol (SMTP) to transfer the message to their mail server. From there, the mail server knocks on the door of your network’s mail server (where your mailbox lives), and if your server is reachable then the message is sent. All of that happens regardless of what sort of email system you have in place. From this point, however, you have a choice. There are basically three different ways that mail can be delivered from your mailbox on the server to an email client or hand held device for your convenience.


POP3 is the oldest mail delivery protocol that is still in use today (and in fact there were POP1 and POP2 which preceded it.) POP stands for Post Office Protocol because your mail server acts as the “post office” for your mail. Mail is delivered to a central mail server. Your computer connects periodically to the server where mail is stored, to see if any messages have arrived. If they have, your computer downloads the messages, and then disconnects from the server. Traditionally, when the messages are downloaded to your computer, they are also deleted from the server where they are stored. This mail protocol was designed with dial-up users in mind, because it does not require a constant internet connection to allow mail to be viewed or manipulated. There are major disadvantages to POP3 however, such as the fact that mail is stored on your computer instead of on the server. This means that if your hard drive crashes you could lose all mail permanently. Furthermore, corruption is frequent for large messages and mailboxes, which results in trouble downloading new messages. Finally, setting up a hand held to check a POP3 account can be complicated and result in mail being delivered to your handheld but not your computer or vice versa.


Internet Message Access Protocol, or IMAP, was developed in 1986 as an improvement over POP. While in POP the computer connects to the mail server and downloads messages to be viewed, with IMAP the messages are viewed while they remain on the server. This allows for multiple computers or devices to access the same mailbox simultaneously while maintaining synchronization. This means you can access your mail from home, the office, or your mobile device and you will be seeing the same thing in each location because they are all being viewed on the server. Additionally, IMAP more reliably handles both large messages and large numbers of messages in a mailbox.

Proprietary Systems

Microsoft Exchange

Microsoft Exchange is a proprietary mail delivery program introduced by Microsoft in 1996. It combines the best attributes of both POP and IMAP, along with more robust management and customization abilities. Microsoft Exchange allows you to view mail while it is on the server (like IMAP), and also archive it into a local file if necessary (like POP3). It is also capable of dealing with larger mailbox sizes than either POP or IMAP. Additionally, Microsoft Exchange allows the backup and synchronization of more than just email. When used with Microsoft Outlook, contact lists, calendars, notes, tasks and more can be synchronized with a server across multiple devices, and also shared with other users. Exchange is also configurable for an application called Outlook Web Access or OWA, which mimics the look, feel, and accessibility of Microsoft Outlook in a web site, and can be logged into from any computer connected to the internet. In short, Microsoft Exchange is the state of the art in terms of office productivity.

Microsoft’s newest Office version, Office365 uses Microsoft Exchange to deliver a robust, easily managed, fully-featured mail host while still being entirely in the cloud to avoid the need for an expensive on-premises mail server.

Gmail, Yahoo Mail

Gmail and Yahoo mail rely on standard SMTP and IMAP protocols for sending and receiving to external systems, but also use their own non-standard protocols to access mail box accounts within their own mail server system.

So you see, there’s plenty more going on behind the scenes when you hit that “send” button. Think about how your mail is being delivered, and whether switching to something else could be beneficial for your company. Afterward, take comfort in the knowledge that your technical foray into the darkest depths of web based communications may have saved you a great deal of time and inconvenience down the line.