Commands directed to a mail server take the form of a mail message addressed to

mailserv@mail-server-host

where mail-server-host is the host name of the machine running the mail server. You need to obtain this name from your system manager. The text of the message contains mail server commands, one command per line.

Mail server command names are not case sensitive themselves. MAILSERV commands preserve the case of specified file names.

For example, suppose the address of a mail server is mailserv@example.com. To obtain a help message from the server as well as a list of the available files and mailing lists, you would send a message much like the one shown in Example 4-1.¹

Example 4-1 Sending Commands to a Mail Server

% mail mailserv@example.com HELP INDEX LISTS [CTRL/D] %

After a short while, you will receive back three messages from the mail server: the first message in response to the HELP command, the second in response to the INDEX command, and the third in response to the LISTS command. If your command specifications are in error, then the mail server will send you an error notification.

Typically, mail from the mail server will have a reply address which differs from the address you use to send commands to it. This is intentional and is done to prevent potential mail loops. One consequence of this is that you cannot direct further commands to the server by replying to messages from it. You must always initiate a new message with the send command; you cannot use the reply command.

A brief description of the available commands is given in Table 4-1; complete descriptions begin in Section 4.2.

Table 4-1 Summary of Mail and List Server Commands

Command	Description
DIRECTORY	Obtain directory listing of available files
DIRECTORY/LIST	Obtain directory listing of available mailing lists
ENCODING	Set default file transmission encoding
END	Terminate processing, accept no additional commands
EXIT	Same as END
FINISH	Same as END
HELP	Retrieve the server-specific help information
INDEX	Retrieve the index of available files
LISTS	Retrieve the index of available mailing lists
MAXIMUM	Set maximum message size; large messages will be divided into several messages, each smaller than this size
MODE	Set the default file reading mode
PURGE/LIST 1	Purge comment lines (such as unsubscribed addresses) from the membership list
QUIT	Same as END
SEND	Retrieve the specified files
SEND/LIST 1	Retrieve the membership list for a given mailing list
SEND/LIST/COMMENTS 1	Retrieve the membership list for a given mailing list, including members' RFC 822 comment fields
SEND/LIST/NOCOMMENTS 1	Retrieve the membership list for a given mailing list, stripping members' RFC 822 comment fields
STOP	Same as END
SUBSCRIBE	Subscribe to a mailing list
UNSUBSCRIBE	Unsubscribe from a mailing list