User:Erbingha/POP v. IMAP

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There are two major methods of approaching email delivery at NC State. One is called POP mail and is the way in which your email has been handled up to this point. However, IMAP mail is the standard for all incoming freshmen and new faculty/staff and has been for a while now. Anyone still using POP (without specific reasons to prevent the move), should make the move to IMAP.

Similarities Between POP and IMAP

Most important to the user is the question of how the change from POP to IMAP will affect getting one's mail. Very simply, the switch to IMAP should not have a large impact on getting your mail. All major email clients (Eudora, Outlook, Outlook Express, Netscape Messenger, pine) can use IMAP as well as POP, so the way that you interact with your mail will be virtually the same as it has been in the past.

Differences Between POP and IMAP

The main change between the two mail handling methods is a difference in fundamental approaches to dealing with email. In order to understand the differences between them, you must first look at each method's process from receipt of an email to delivery at its destination.

POP - Post Office Protocol

When a POP server receives an email, the server consults its list of available recipients. If the address on the email matches one of the server's recipients, the POP server adds the message to the recipient's mailbox. The entire email is immediately downloaded and ready to be read by the user.

In the past, email has been stored in AFS space, on users' K: drives. When the user had too much data on K:, be it email or other data, they could no longer store any kind of file, regardless of whether it was email, graphic file, or Word document. If a user was out of space for new mail, the mail server would return the email to the sender with a notice that the desired recipient was over quota.

IMAP - Internet Message Access Protocol

When an IMAP server receives an email, the server again matches the addressee against its list of available mailboxes. However, when a program like Eudora asks the server for email, the server only passes the program a list of headers. Only when the user clicks to read a specific email is that email copied to the local machine, and then only on temporary basis. All email is kept on the mail server, rather than in users' K: or C: drives.

If a user runs out of space on the IMAP server, messages get queued. Once enough email is deleted to bring the mailbox size back below the quota limit, the messages from the queue will be delivered until either all messages have been delivered or the mailbox is again over quota. Messages will be held in the queuing system for a few days before being returned to the sender with a notice that the desired recipient is over quota.

Notable Differences

So what new things should users be aware of when using the new IMAP system?

  • Quota: Mail is now kept on remote servers, rather than on the K: drive. Since space on the mail servers is limited, there is a 20 MB limit on email. Also, since the IMAP mail servers do not belong to ITECS, additional mail quota can not be granted by ITECS. It is the responsibility of the user to manage their mail so that they remain under quota. Additional quota space may be purchased from NCSU's IMAP Quota pages. The prices are extremely reasonable.
  • Access from Multiple Locations: IMAP, being on a separate server, allows one to check email from a number of places without having to why about synchronizing inboxes. Anyone who checks their email from more than one location REALLY needs to move over to IMAP.
  • Webmail: Since mail for all users is now kept on a small number of centralized servers, it is now possible to serve the contents of users' mailboxes out over a network connection. Thus, all IMAP subscribers can access their email from anywhere in the world using Webmail. By going to, users can send, receive, and manage their email messages. Any messages stored in the K: space will not be visible in Webmail. In Eudora, this consists of any folders under the "Eudora" heading rather than under the "" heading, or in Outlook (and OE), the 'Local / Personal Folders'.
  • Deletion: A "Trash" folder will no longer be used to store throw-away email. Instead, mail messages will be marked as deleted and remain in the original folder. Only by selecting "Purge Messages" from the Message menu in Eudora will the messages go away. It should also be noted that once the mailbox has been purged, the deleted messages are permanently erased.
  • Organization: Other features related to email will remain the same. Users will still be able to sort their email into subfolders and retain copies of anything they send, just as they have before. Users will be able to copy or move important emails from the IMAP server to their K: space. It is also possible to move messages and folders from K: to the IMAP server (as long as the user stays below the 20 MB quota limit). However, as mentioned earlier, messages stored on the K: drive will not be accessible through Webmail. Messages are transferred to/from the IMAP server using the same steps used to transfer messages between any other folders in your email client.
  • Virus Protection/Handling: There have been instances where Norton Antivirus will detect a virus within your email inbox and being unable to remove it, Norton will quarantine the virus, and the inbox with it. POP inboxes are a single file and NAV cannot just block the one email. While detecting and containing a virus is good, it does mean you've just lost your inbox. Due to how IMAP email is handled, NAV can block individual emails rather than the entire inbox.

Getting IMAP

Fortunately, the procedure for moving from POP to IMAP is relatively simple. The website has a page that allows users to request their email be changed to the IMAP servers, as well as several pages of documentation on the workings of IMAP. To go directly to the IMAP change-over page, access You will be asked for your login ID and password. You will then see the final information page followed by a button that reads "Yes, change to IMAP". Once that button is pressed, final confirmation is all that is necessary to complete the process. This will prevent your checking of email (not receipt - you'll still receive email) for the rest of the day, so its best to do so when you're ready to leave for the day.

NOTE: Directions on the final information page (change_to_imap.html) should be followed in order to ensure that existing unchecked email on the POP server is not delayed. It will be forwarded to your IMAP mailbox, but the IMAP space may take up to 24 hours to create.

Once created, you'll have to tell your email client to use your new IMAP account. Those using Outlook/Oulook Express can find an article here explaining how to do so.