IMAP vs. POP3 E-mail Accounts

Basically IMAP and POP (version 3) are different protocols for handling e-mail. Each has its own unique function and purpose. The protocols allow IMAP to deal with e-mail in a different way than POP does. POP is basically a flow through entity—it just passes on the information to you at your e-mail program. IMAP on the other hand, is interactive with your e-mail program. Let’s take a look at the uniqueness of both.

POP3

POP stands for “Post Office Protocol”. It works very simply. When the POP e-mail server receives e-mail it stores it on the server until you to request it. By simply opening your email program (e.g., Outlook) you request the e-mail from the server by pressing the “Send” or “Receive” button. The e-mail program in essence asks the server if there is any mail waiting. If there is, it tells the server to sends it to your email program.

When the POP server receives your request for mail, it sends the entire message to your e-mail program. Once you receive the email, your email software tells the server to remove the email from the server. So the message is no longer stored on the server unless you specifically tell it to keep a copy.

IMAP

IMAP stands for “Internet Message Access Protocol”. It allows you to download e-mails from the server to your e-mail program the same as POP does. However, the difference is that when you request your e-mail from the server it sends a copy rather than sending the entire e-mail. It keeps a copy of the e-mail on the server while simultaneously keeping a copy on your computer.

You may be wondering what happens if you have certain messages on your local computer and IMAP has different messages on the IMAP mail server? IMAP has built in intelligence to handle this task. When you connect the IMAP mail server with your local computer, it senses that there are differences between the local computer and the mail server. It then synchronizes both so that they have the same information. It uses the date / time stamp to deturmine if a message should be uploaded to the server, downloaded to the device or deleted from either.

For example, if you delete messages, compose more and have sent others, this information will be synced up with the IMAP server so that the IMAP server will delete the copies of the messages that were deleted. By the time you log off the IMAP server you have two complete copies of all of the e-mail tasks performed: one on the IMAP server and one on your local computer.

Advantages and Disadvantages
POP	IMAP
Designed for all users (one of the first protocols developed to work within TCP/IP.	Developed by corporations for corporate customers that have a full time email staff and LOTS of storage space.
Relatively straightforward and faster (sends your e-mails and gets e-mails from you)	Slower but more redundant
Everything you do is on your local computer. If you have multiple computers you will need to adjust you email clients to allow for synchronization of incoming email and / or the deletion of items no longer wanted on the server, like spam (by deleting them from your deleted email folder).	Keeps a copy of everything you do on the server. Received email, sent email and even the headers for deleted email.
Takes up less space on the server. Less space = lower cost.	Takes up more space on the server. More space = higher cost.
If you lose e-mails on your computer you have lost them forever unless you have backed up a copy of your email to a alternate location. Most, if not all, email clients have a method of backing up your email to an alternate location.	All your email is on the same server as your web site. NEVER recommended as we get attacked every day. If someone gets access to your account they have all your email and customers. If someone hacks your account and removes all your email messages they will be removed from your device when it connects to the server.