The following table lists some common e-mail tasks and compares how they are carried out with the POP protocol to how they're carried out with the IMAP protocol:
What does it stand for?
POP: Post Office Protocol
IMAP: Internet Message Access Protocol
Which protocol would suit me best?
POP: If you access mail using only one computer e.g. your office PC or a laptop.
IMAP: If you want to access your mail from multiple computers or locations.
Which mail programs can I use?
POP: All mail programs or clients have POP capability
IMAP: Most mail programs have IMAP capability and you will also be able to access your mail via a web page using any web browser.
Some Common Tasks of POP & IMAP:
A] Check for incoming mail:
POP: By default, incoming messages are transferred to your local machine when you check your incoming mail. Only new messages are available if you connect to the server using a PC other than your normal one. You are connected to the server only for the transfer of messages.
IMAP: By default, incoming messages stay on the server when you check your mail - only headers are transferred with full messages only downloaded when selected for reading. All your messages are always available no matter where or how you connect to the server. You remain connected to the server whilst you deal with mail but some clients allow for off-line working.
B] Read and respond to mail:
POP: Reading and responding to messages is done on your local machine.
IMAP: We can read and respond to messages directly on the server but you can also read and respond to messages on your local machine, after downloading for offline working (depending on client). When you reconnect, your mailboxes are resynchronised to reflect the changes you have made.
C] Create mailboxes for storing messages:
POP: Creating mailboxes can be done only on your local machine.
IMAP: You can create mailboxes directly on the server. By default, an Inbox is automatically created on the server when you begin using IMAP. The Inbox functions as the master mailbox (or folder) as well as the mailbox for incoming messages. All other mailboxes, including a trash box, need to be created within the Inbox.
D] Move messages in and out of mailboxes:
POP: You can move messages in and out of mailboxes only on your local machine.
IMAP: You can move messages in and out of mailboxes on the server and on your local machine.
E] Transfer messages from local machine to server and vice versa:
POP: You cannot transfer any messages from your local machine to the server. Messages are automatically transferred from the server to your local machine when you check your incoming mail.
IMAP: You can transfer individual messages from mailboxes on your local machine into mailboxes on the server and vice versa.
F] Delete selected messages on the server:
POP: When using some clients (e.g. Eudora), if you specified to leave messages on the server, you can delete individual messages left there.
IMAP: You can delete individual messages and groups of messages directly on the server as well as on your local machine.
With IMAP (Internet Message Access Protocol) you read your mail while it is still on the mail server. Because your mail remains on the server, you can access it from any IMAP-configured computer with internet access. Whether you are at work, at home, or traveling around the world, all of your messages are available to you.
POP (Post Office Protocol), on the other hand, is designed to handle offline operations. POP downloads e-mail to the PC, generally removing it from the central server. After messages are moved onto the desktop of the current local computer and deleted from the server, you then manipulate them on your desktop. Therefore, POP e-mail is only available on that specific desktop computer. e-mail stored locally using POP may not have a back-up system in place and would be vulnerable to loss in the event of a computer crash, whereas with IMAP, e-mail messages and folders are backed up nightly by ITS and are available in case of loss.
Because POP downloads messages to the local PC, it is possible to disconnect from the server while manipulating messages. Some people find this ability to work offline very useful and therefore prefer using POP. However, IMAP can also be set to work offline if desired, because messages can be moved onto the local computer as with POP. This brings up the same issues stated above, namely that messages are no longer available from other computers and that one must devise a local back-up solution.
POP also causes issues that affect all users, even those who do not use POP. For example, performance problems often occur server-wide when just a few people using POP configure their clients to leave the mail on server. This results in enormous inboxes which severly slow down the server every time the inbox is accessed. This performance decrease affects everyone.
Because of its many advantages, IMAP is the preferred method of connection. So start configuring IMAP for your email Client and check the difference.
