You can communicate with the CIT List Server (ListProc) software by sending e-mail. There are two types of e-mail you might need to send, and it's important to send each type to the right place:

To perform various operations such as joining or leaving a list, or setting your options, send e-mail messages containing commands to listproc@cornell.edu.

Please note that ListProc is a computer, not a human, so it is very easy to confuse it with typos or small errors. The computer cannot determine what you mean to say, it can interpret only what you actually say. After ListProc processes your command, it will send you a response -- successful commands will result in the action or information you need, while unsuccessful ones will generate an error message.

To send a message for the list's subscribers to read, send messages to the e-mail address of the list. For example, if your history class had set up a mailing list called history234-L, to contribute to the electronic discussion for this class, you would send e-mail to history234-L@cornell.edu.

This page describes the format you need to use for sending commands to ListProc. Other sections of this guide show the various commands you can send.

Throughout the remainder of this guide you will see a variety of commands that you must send to ListProc via e-mail whenever you wish to interact with it. These commands vary in length and scope; some require only one or two words while others need several and include optional settings.

The following points apply to all commands sent to listproc@cornell.edu:

• Leave "Subject" blank

• Upper/lowercase doesn't matter (usually)

• Avoid formatted text

• Abbreviated commands

• Long commands

• Maximum command length

• Multiple commands in one message

• Your e-mail address identifies you

• Problems with "mailing loops"

Leave the "Subject" line of your e-mail message blank -- ListProc reads only the body of the message for commands.

You can submit commands in lowercase, uppercase, or mixed-case characters (there are a few exceptions to this rule involving passwords and archive names; they are noted when the individual commands are described).

Messages sent to ListProc must not contain any formatted text (bold, underline, color, italics, different fonts or font sizes, etc.). Also, they cannot inclulde HTML, MsWord, RTF, attachments, PGP, MIME, vcards, etc. Messages sent to the mailing list can contain styled text, but in general we recommend that avoid using styled text.

If you are using Eudora to send e-mail, you can either have all your messages sent out without formatting, or have Eudora ask you if it should send style info with each message. (On a Windows computer, go to the Tools menu, choose Options, then select "Styled Text" in the scroll box on the left. On a Macintosh, go to the Special menu, choose Settings, then select "Styled Text" in the scroll box on the left.)

You can abbreviate commands, but you must enter at least the first three characters, plus as many additional characters as needed to distinguish one from another. For example, you may shorten the subscribe command to sub.

A complete list of all ListProc commands cannot be provided here -- if you receive an error with an abbreviated command, try again with additional characters or use the complete command instead.

Each command must occupy a single line. If your request is more than 80 characters long (this will only happen rarely), you must use an ampersand -- "&" -- to indicate that the next line forms part of the current command. For example, if you want to change the e-mail address where you receive messages from a list that happens to have a very long name, you must break the command into two lines as shown below:

Although this sample command spans two physical lines, the server considers it to be a single command. Be sure to press the Return or Enter key after typing the "&" character. There cannot be any spaces or any other characters after the ampersand.

Be cautious with line length. Many programs used to compose mail, such as Eudora, vary their definition of line length (how many characters fit across the screen) depending on the screen font.

Programs that allow you to enter more than 80 characters per line often cause problems for ListProc. While the mail travels on its way to the CIT List Server, one of the programs that processes it may break lines longer than 80 characters into multiple lines that are 80 characters or fewer. When your mail ends up at ListProc, in these cases, your single-line command will span multiple lines and will be rejected.

To avoid these problems, limit your line lengths on commands to 80 characters or less, even though your mail program may be able to handle more. Use the ampersand, as desribed above, for commands that require more than 80 characters. When in doubt, use caution and the "&" character to break your command into multiple lines.

Individual commands are limited to a maximum length of 1022 characters. (Commands that use the ampersand to span multiple lines all count as one command, so they are subject to the 1022 character limit.) Any characters after that limit will be ignored, and ListProc will process the command without them. (It is extremely unlikely that you will ever need a command this long.)

You can submit multiple commands in the same message as long as each one ends with an Enter or Return. Do not use ampersands to connect separate commands.

ListProc processes commands sequentially, sending a separate response for each one (so if you include three commands in a single message, you will receive three replies from ListProc). If one of the commands contain a syntax error, ListProc will ignore it, but will continue to process succeeding commands. If the command is written correctly, however, but generates an error response, ListProc will not process subsequent commands.

When you subscribe to a mailing list, ListProc creates an entry for you in the subscriber file. That entry identifies you using the e-mail address listed on the "From" line in your message. Subsequently, when you send certain ListProc commands (for example, unsubscribe), it compares the "From:" line on your message with the entry in the subscriber file. If it finds a match, ListProc processes the command, otherwise it rejects it. (ListProc conducts a similar search for messages sent to "restricted posting" lists, where only subscribers may post.)

Problems with a subscriber's address occasionally create a "mailing loop." Such a loop may generate hundreds of messages within a short time as one system sends mail to the list, which in turn sends it right back for redistribution. The ListProc software tries to detect possible loops automatically, and will delete any address suspected of causing loops.

If you suddenly stop receiving mail from a list, you may want to contact the list owner to determine whether you have been dropped for this reason (go to Getting Help for information on how to contact your list's owner).