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HOWTO Documents > IMAP at CCIS > IMAP Access to Mail at CCIS - General Overview

IMAP (Internet Message Access Protocol) is a method for remotely reading mail - both your incoming mailbox and folders you've stored old mail into. This document describes in general how IMAP is deployed at CCS. It doesn't describe how to configure a particular mail reader to use IMAP; you'll need to consult documentation specific to your mail reader for that. We have documentation available describing how to read CCS email via IMAP with a few popular mail readers.

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See also...

See also the following guides for configuring particular mail clients (mail-reading programs) to communicate with our IMAP server:

•	Configuring Eudora to access your CCIS email via IMAP
•	Configuring Microsoft Outlook (not Outlook Express) to access your CCIS email via IMAP
•	Configuring Microsoft Outlook Express to access your CCIS email via IMAP
•	Configuring Pine to access your CCIS email via IMAP

You will probably also need the information in the following document in order to send mail via CCIS. You can ignore the parts about retrieving your mail with POP.

•	SSH Tunneling: How to securely send and retrieve your CCIS mail via SSH.

If you have questions about IMAP access to CCIS mailboxes that these documents don't answer, or comments or questions about the documentation itself, please send them to systems@ccs.neu.edu.

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What are the advantages of IMAP?

IMAP lets you access the same mail folders from different IMAP-capable mail readers on different computers, so you can store all your mail at CCIS, but access it from elsewhere (e.g. from home, at a conference, etc.). It also lets you use the same mail reader on the same computer to access mail on multiple sites, provided all the sites support IMAP.

At CCIS, we use the Secure Sockets Layer (SSL) to encrypt all IMAP traffic between CCIS and your machine, so neither your password nor your mail is transmitted in plain-text over the Internet. It's about as secure as using ssh to log in to a CCIS Unix machine remotely and read your mail that way.

IMAP has much better support for email attachments than POP. If you're reading a message with a large attachment, IMAP doesn't transfer the attachment until you actually want to save or view it, so if you regularly get attachments in your mail (and don't always save or view them), IMAP will speed up checking your mail.

How IMAP at CCIS works

In order to use IMAP to get to your CCIS email, you will need a mail reader that understands the IMAP protocol and supports the Secure Sockets Layer (SSL) standard for network encryption. You will need to set your mail reader up to talk to our IMAP server, whose name is imap.ccs.neu.edu, using SSL, and depending on your mail reader and how your mail is stored, you'll probably also need to tell it where in your account you store your mail folders.

When you check your CCIS email, your mail reader will first establish a secure connection to the CCIS IMAP server using SSL. Then it will authenticate you to the IMAP server, by asking for your CCIS login name and password. (At CCIS, this is secure because we use SSL; not all other IMAP servers do.)

Once you are authenticated, you'll have access to your CCIS incoming mailbox. You may also have access to other mail folders in your home directory. Depending on your mail program, you may need to subscribe to particular mail folders or collections of mail folders, by telling your mail program where to find them in your CCIS account. Some (ill-behaved) mail programs will try to show you the entire contents of your CCIS Unix home directory, including all your other files as well as your mail.

Once you've done that, you can read your new mail, file it into existing folders (or create new folders), and also access mail stored in folders. You can mark messages for deletion and then `expunge' all the deleted mail (actually removing it). Depending on the capabilities of your mail client, you may be able to sort or filter your mail as well.

Settings and configuration

You'll need to tell your mail client the name of CCIS' IMAP server machine, which is imap.ccs.neu.edu, and that you are using SSL. (You might do the latter by clicking a check button that says something about SSL or using a secure connection, or by telling your client to connect to port 993 on the server, which is the port used for SSL-enabled IMAP connections.)

You'll also need to tell the client where to find your mail folders under your home directory, and what folders you want to ‘subscribe’ to. (For instance, Mozilla's mail client lets you specify the directory your mail folders are in as the ‘IMAP server directory’, which is on the Advanced... panel under Server Settings for your account, and Pine lists this as the ‘Path:’ field when you add a new folder collection.)

(Your mail client will also need to know how to send mail, and that's more complicated if you want to do it through CCIS. We have an SSH tunneling document at http://www.ccs.neu.edu/howto/howto-sshtunnel.html that describes how to do that. You'll only need the port-25 part of the tunnel, to send mail via SMTP. You'll be reading your mail over SSL-encrypted IMAP rather than POP as described on that page. If you're connecting to our outgoing mail server from within CCIS, you can skip the tunneling part and just specify the outgoing SMTP server as smtp.ccs.neu.edu - not the same as the name of the IMAP server.)

Most mail clients also require you to specify your real name and your email address (the latter being yourlogin@ccs.neu.edu). While you're setting options, please turn off composition of HTML messages - you should never send HTML messages to somebody who hasn't specifically asked for them.

In order to connect to our IMAP server, you will need to provide your CCIS login name and (Unix) password. You should not have your mail client store your password - instead, you should type it each time you connect. If your mail client saves your password, anybody who gets physical access to your machine can use the password to break in to your CCIS Unix account. (It's fine to let your mail client store the login name, though.)

Deleting mail

IMAP distinguishes the actions of marking a message to be deleted and actually removing it from the server. The first action is typically called deleting mail, and the second one expunging deleted mail from a folder. (Exactly what you see on the screen will depend on your mail reader, of course.) Usually, the delete command in your mail reader will just mark a message for deletion, and you have to expunge the marked messages before you quit your mail reader, or they'll still be there the next time you check your mail.

Some mail readers will ask you if you want to expunge mail if there are any messages left which are marked for deletion when you quit, but most won't.

Advanced features

Most IMAP users will not need to pay any attention to the information in this section.

MH-format mail folders

If you keep your mail in MH format - i.e. if you use MH commands like inc, show, and refile on the command line to read your mail, or the EXMH application- you can still access those folders via IMAP. However, you'll need to specify ‘#mh/’ as the path to your mail folders. (Actually, that's not a path, or rather it's an empty one, but the ‘#mh’ part specifies that you're looking for folders in the MH ‘namespace’in IMAP terms.) Then our IMAP server will check to see where you keep your MH folders (by looking at the file .mh_profile in your home directory), and make those folders available. Depending on the particular client you're using, you may need to specify ‘#mhinbox’ to get at your MH inbox folder, since the name ‘inbox’ (typically spelt ‘INBOX‘) is reserved for your incoming mailbox, where mail is delivered by the system (i.e. where you inc your mail from). An alternative if you're using such a client is to make a symlink to your inbox folder from your MH directory with a different name. (Some mail clients, like Mozilla, are smart enough to deal with this transparently and present your MH inbox as #mh/inbox, where you'd expect it.)