Thunderbird
Choosing IMAP or POP

Your e-mail client can handle your mail in two different ways: using IMAP or using POP. This page briefly compares the pros and cons.

Boiled down to simplest terms:

• If you always view your e-mail on one computer, POP probably meets your needs, and you may find it simpler to use. But please read the other factors below for more information.
• If you want to have access to your messages from more than one computer, IMAP is better able to provide that ability. But please read the other factors below for more information.
  

Overview

IMAP considerations

POP considerations

Which am I using now (current Thunderbird users)?

Which am I using now (Eudora users planning to switch to Thunderbird)?

IMAP (Internet Message Access Protocol):

• All your messages are available to you from multiple locations, and you can set up folders and mailboxes on the server, allowing you to organize your messages. You can also filter your messages and use colors to identify them.
• Only the message headers are retrieved automatically, so you can review what's new very quickly, and only download the information you want. As a side effect, attachments are not downloaded until you open the message and save the attachments. If you delete the message without downloading and saving the attachment, the attachment file is lost. (You can, of course, ask the sender to send it again.)
• People using IMAP typically store most of their e-mail on the mail server (so it will be available to them no matter where they are when they check their mail). You will get 300 MB of storage, which is a *lot* of space for messages (most of Cornell's peer institutions provide less than half that amount), but can fill quickly if you receive large attachments. When you fill 70% of your space, you will receive an automatic message advising that you delete messages or move them to local storage. You will get a second, more emphatic message when you reach 90%. If you completely fill your storage space, incoming e-mail messages will not reach you, and the sender will be notified that their message could not be delivered.
• You can use IMAP with Thunderbird and with Eudora (version 5.2 or higher), but many people have reported problems using a Eudora-IMAP combination. Both the uPortal.Cornell E-mail channel and WebMail use IMAP.

POP (Post Office Protocol):

• Your messages are automatically saved to your local hard disk. However, this means you may have to wait while your messages and attachments (including spam and other unwanted information) download.
• You can retrieve your messages and then read them (and prepare replies) while not connected to the network
• Once you retrieve your messages, they are not available to you from another computer, unless you set your options to leave your messages on the server. If you leave messages on the server, you cannot tell at a glance which messages you have already read. You cannot organize your messages on the server.
• You can use POP with Thunderbird or with Eudora. Although both the uPortal.Cornell E-mail channel and WebMail use IMAP, you can still use them even if you choose to use POP with Thunderbird or Eudora.