The New Servers

The Computer Center has recently obtained two new servers, jointly known as mailserv.uic.edu, which will handle all outgoing mail at UIC, as well as most incoming mail. To access mail on these, you need to use Eudora or WebMail (or some other POP- or IMAP-capable mail client, not supported by the computer center). No direct login to these servers via telnet is possible, hence you can not use pine on them.

Eudora is an email-application running on your PC or Macintosh. It retrieves your email from a server and stores it on your hard drive, as opposed to terminal-based programs like pine or CMS MAIL or NOTE. When you use one of those latter programs, you just use your desktop computer as a dumb terminal to connect to the server. All processing is done on the server (so if your connection is very slow, you have to type very slowly to see what you are typing).

In contrast, with Eudora, or other similar programs such as Netscape Messenger, Microsoft Outlook, or Pegasus, you do all processing on your desktop machine. This is where you create messages, that Eudora transfers to the server only when you are done typing and ready to send out the note. Because this is a bit like going to the post office (you pick up your mail, go home to write a reply, and then go again to the post office for sending it), the classical protocol these applications use to transfer messages is called Post Office Protocol, or short POP (often the version number is attached, as in POP3).

What now is the post office? It is a server program running on various of our main computer center servers, namely mailserv, tigger and icarus. (There currently is also a POP-server running on CMS, called popserv#.cc.uic.edu, but that will be turned off during the summer of 1999.) These programs use a common file area, the so-called spool, for storing your incoming mail into a file named after your NetID. This file is your INBOX, and is used by the server-based pine email program as well (on tigger and icarus only). When Eudora connects to the server to see whether there is any new mail for you, it copies all messages in the INBOX to a temporary file (so new mail can still come in to your INBOX) and downloads them to your desktop. It will then normally erase the mail on the server, so there is again space for new incoming mail. You can change this behavior by choosing the "Leave Mail On Server" option in Eudora's configuration. That can be useful e.g. if you want to check your mail from the office, but then download it to your home machine for safekeeping. Be careful though to tell Eudora that it should automatically delete files from the server after 30 or so days, so your INBOX does not fill up.

The disadvantage of this method is that mail is stored only on your personal machine (unless you use LMOS), and is not accessible to you from elsewhere. If you want to read your mail from somewhere else, say at a conference, you could of course use a POP-client such as Eudora to retrieve your mail, but you cannot access older messages from there for reference or replies. You would also have to delete your mail from that other machine afterwards, and make sure you send copies of all outgoing mail to yourself for your records. In general, sending yourself a copy of everything is the only way you can keep sent messages visible for both locations. And due to rather limited filespace on tigger and icarus you won't be able to keep much mail there anyway, so it would be a constant hassle to clean up.

An older solution to this problem is pine. You can telnet to tigger or icarus and read your mail with pine, replying and keeping copies on the server. pine supports the MIME-protocol, so it can handle file-attachments properly. But there are still two big problems:

• pine is a terminal-based program, hence uses an ASCII-character display, not a graphical interface. It is thus unable to display messages in HTML or rich-text-format, nor can it handle graphics or sounds embedded in the message. File-attachments must be saved, and then transferred via ftp to your PC (if they are PC-related files, such as word-processor documents).
• Spool space on the servers is limited, so you have only a certain quota, which fills up fast. The grim reaper program, well known from CMS, will delete messages over that limit from your INBOX, be they too old or too large. Thus you need to save messages you want to keep into your personal file area, which is also quite limited in size. In CMS, this step was called RECEIVE, and if you used the MAIL command, you automatically always RECEIVEd all your mail. On Unix, using pine, you type s for save to store messages in your private mail-folders, such as read-mail. There they are safe from the grim reaper. But when your filespace fills up, you will have to ftp these over to your desktop machine at some point. The nice thing is that pine mailboxes and Eudora mailboxes have the same format, so it is easy to ftp them over to your desktop machine (using ASCII mode) and opening them in Eudora. You just need to add an extension of .mbx to the filename (and give the new mailbox a unique name!), put the file into your mail-directory, and restart Eudora. It will then recognize the new mailbox.

A better solution is here now: IMAP (short for Internet Message Access Protocol). This protocol is useful mostly for those with a direct network-connection, or those who dial in and stay connected while reading/answering their mail. For those with short connections (say, using the UIC-Express dial-in lines), the POP protocol remains the way to go.

Just as with the POP protocol, your IMAP client program might theoretically use the so-called offline access method. This means that it connects to the server to check for new mail, picks it up, and disconnects. You would read your mail while disconnected, respond to some, move other messages into different folders, and discard a lot. When you then connect again to the server to send messages and check for any new ones, the big difference appears: under the IMAP protocol, (most of) your mail is kept on the server, so your client will now synchronize with the server (moving, editing, discarding -- copying all the moves you made on your desktop machine). Then you can later access your mail from some other machine with any IMAP client (this time perhaps WebMail, or MS Outlook 98, or the newest Netscape Messenger) and still find all your mail, neatly organized as you left it. Unfortunately, the current version of Eudora (4.1) does not yet support offline access. You need to be connected to the server to view any remote mailbox's content or do any operation on a remote mailbox.

For detailed instructions on using IMAP, check the December98 issue of the A3C Connection, the Academic Computing and Communications Center's newsletter, or the later pages of these seminar materials.