What IMAP Email Can Do for You

What Is Wrong with POP Email Accounts?

Wow! That's neat!
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IMAP is short for "Internet Message Access Protocol", and internet message access is precisely what the protocol allows you to do.

POP and IMAP, the Email Access Protocols

When you retrieve email messages received at your inbox from a mail server using an email program (on a computer, say, or a mobile phone), the server and your program (acting as the client) have, in email's early days, used the Post Office Protocol (POP) to communicate.

Downloading messages to an email program is what IMAP and POP share. While POP was designed to do merely that, though, IMAP provides lots of useful functionality more.

POP and Its Problem with Multiple Computers or Devices

In a typical POP session, your email program will download all newly arrived messages, and then delete those emails from the server immediately. This procedure preserves space on the server and works perfectly fine, of course—provided you access your email from only one computer or device and exactly one email program.

As soon as you try to work on your email from more than one machine (a desktop at work, a laptop at home and a phone, for example), POP email becomes and a major headache to manage:

  • Incoming emails start to be missing from all but one of your email programs,
  • message cannot be downloaded easily again (so you turn to forwarding and redirecting messages to yourself),
  • you have to re-create rules everywhere and
  • sent mail is usually only available on the machine from which you sent it.

This is just a short list of the things that tend to go awry with POP email.

The Root of Troubled POP Email Access

At the root of all these problems lies POP's concept of offline email access.

Email messages are delivered to the server. An email program downloads them to your computer and deletes all messages from the server immediately. This means they are all local to the machine and email program. This is where you delete, reply, sort and file messages to folders.

Now, how can IMAP improve upon this?

While IMAP can be used for offline email access in very much the same way as POP, it also provides online email processing that automatically synchronizes actions between email programs.

IMAP: Your Email Inbox in the Cloud

What does that mean? Basically, you operate on the mailbox that resides on the server as if it were local to your machine.

Messages are not downloaded and deleted immediately but reside on the server.

The email program keeps a local copy only for display.

On the IMAP server, the messages can be marked with flags such as "seen", "deleted", "answered", "flagged". (IMAP also supports user-defined flags; these are rarely used, though.)

Synchronized Access to All Email Folders

What else do you do with messages in your email client? You would file them in different folders, and you would search the folders for specific messages. Both can be done via IMAP right at the server as well.

You can set up email folders and file messages in them, and you can tell the server to search its repository and deliver the results to you.

Since you manipulate the emails directly at the server, using multiple computers to access the same email account is a snap.

It is even possible to have the same account and folder open in a web interface, for example, and on your phone at the same time. Any action you take in one place is automatically mirrored on the server and then the other device.

Shared Folders

IMAP also allows access to shared mailboxes. This is an easy means of sharing information, or to make sure important email (to a support mailbox, for example) is dealt with: all support staff can access the IMAP mailbox, and they will instantly see which messages have been answered and which are still pending.

That is the theory. In practice, shared folders are not frequently used, and support is limited among email servers and programs.

Example IMAP Usage

Imagine Jina, who loves working in the kitchen using her laptop and at the lake with an iPad but also has a computer at work.

When she had a look at her IMAP Inbox just before she left the office, there was an urgent email from John, her boyfriend. We do not know what he wanted to know, but it was important enough for Jina to flag the message as important.

Coming home, Jina had already forgotten about John's message. Thanks to routine, she dragged her portable computer to the kitchen table, though, and checked her inbox. John's message was right there, of course, demanding attention with its red, glowing flag. Jina replied immediately.

The message Jina sent back to John was automatically stored on the IMAP server in the "sent items" folder. On the next day and at the beach, Jina's inbox contained a message from John flagged as "answered", and her reply was readily accessible in the "sent items" folder.