<P>The day of week (Wed) is optional. The time is given as 24 hour format (00:00&#151;23:59) local time. The last field is the time zone in one of several formats.

<BR></P>

<PRE>UT or GMT      Universal/Greenwich Mean Time

EST or EDT     Eastern time zone

CST or CDT     Central time zone

MST or MDT     Mountain time zone

PST or PDT     Pacific time zone

-HHMM          HH hours and MM minutes earlier than UT

+HHMM          HH hours and MM minutes later than UT</PRE>

<P>If EST is Eastern Standards time and EDT is Eastern Daylight Time, you can figure out the abbreviations for the Central, Mountain, and Pacific time zones. The -HHMM format is probably the least confusing_-0500 makes it much easier to translate the time 

to local time than does EST.

<BR></P>

<P>You may also see the following military codes used:

<BR></P>

<PRE>Z          Universal Time

A          UT - 1 hour

M          UT - 12 hours

N          UT + 1 hour

Y          UT + 12 hours</PRE>

<H5 ALIGN="CENTER">

<CENTER><A ID="I17" NAME="I17">

<FONT SIZE=3><B>Don't Sweat the Headers</B>

<BR></FONT></A></CENTER></H5>

<P>If all this header information is giving you information overload, don't sweat it. The really important fields are From, To, Date, and Subject, and it's pretty obvious what those mean. The other information is there in case you need it.

<BR></P>

<H4 ALIGN="CENTER">

<CENTER><A ID="I18" NAME="I18">

<FONT SIZE=3><B>Mail Programs</B>

<BR></FONT></A></CENTER></H4>

<P>There are actually several components involved in sending mail. First there's the hardware: Mail has to be physically transferred somehow, either along a dedicated phone line, via satellite, or over a modem. Then there's the link layer: The systems on 
either end of the hardware connection have to agree on how to communicate with each other. Next is the transport agent: Mail transport agents (MTAs) worry about all the complexities involved in routing mail and sending mail from one site to another. 
Finally, there's the user agent: The mail user agent (MUA) is the software you use to read all your mail, manipulate it, and send your mail. This is what people usually mean when they talk about a &quot;mail program.&quot;

<BR></P>

<P>The first three layers aren't usually your concern, unless the MTA places some special constraints on what you can send. You're concerned with the user agents.

<BR></P>

<P>There are many mail programs you can use. This chapter does not cover any one program, but it covers the elements that are common to them all.

<BR></P>

<H5 ALIGN="CENTER">

<CENTER><A ID="I19" NAME="I19">

<FONT SIZE=3><B>Your Mail Files</B>

<BR></FONT></A></CENTER></H5>

<P>Normally, you have a mail account on whatever computer handles your mail. Often, you can do other things with your account besides access your mail, but that's not important for now. All your new mail, known as incoming mail, is kept in what is usually 

called a mail spool file. It's quite common for your computer to occasionally look at the spool file and notify you if you have new mail. This is your clue to run your mail program.

<BR></P>

<P>Your mail program then grabs all the incoming mail and displays it for your edification. If you don't delete the mail, it is placed in your mailbox file. This is not the same as your incoming mail file&#151;the mailbox file holds all your old mail. Many 

users eventually outgrow the single mailbox and have several for different subjects, but there is almost always a default mailbox used whenever you run your mail program, and this is what is referred to as &quot;your mailbox.&quot;

<BR></P>

<P>If you send mail to someone else, it is sent directly to your site's mail computer, which can do what it pleases with the mail&#151;it either sends it on immediately or saves the mail up to save in batches.

<BR></P>

<H5 ALIGN="CENTER">

<CENTER><A ID="I20" NAME="I20">

<FONT SIZE=3><B>Using Mail Programs</B>

<BR></FONT></A></CENTER></H5>

<P>As mentioned earlier, there are many mail programs, each with their own quirks. But they try to accomplish the same task and tend to present the messages in a similar format. Learning about one mail program will give you the concepts needed to use 
almost any program in existence.

<BR></P>

<H6 ALIGN="CENTER">

<CENTER>

<FONT SIZE=3><B>Message Summaries</B>

<BR></FONT></CENTER></H6>

<P>Almost every program in existence summarizes your messages like this:

<BR></P>

<PRE>FA    1) 14-Dec Tanya Harding      Where can I get a lead pipe? (2457 chars)

F     2) 11-Jan Ken Bibb      rdippold.ps.gz (1/1) (17464 chars)

F     4)  8-Feb Neil Gaiman      Greek Mythology (2576 chars)

F D   5) 10-Feb clinton@whiteho This is a stickup (13786 chars)

FA    6) 15-Feb Robbin Hughes      Re: REX test driver (1451 chars)

U      7) 16-Feb The King      Re: Chili Donuts (2653 chars)</PRE>

<P>There's one line per message. Again, the information for each message won't always be presented in exactly the same format, but the contents should be similar. From left to right for this mail program (named mm90). These lines give the following 
information:

<BR></P>

<UL>

<LI><B>Message flags.</B> Each message has several state variables associated with it. In this case, the flags are whether the message is unread (U), whether I have answered the message , whether the message is deleted , and whether I have flagged the 
message for further attention . Some programs let you give each message one of several priority levels.

<BR>

<BR></LI>

<LI><B>Message number.</B> It helps to be able to refer to a message by a unique identifier for printing, reading, or deleting. Usually, the mail program just calls the first message in your mailbox 1 and counts up from there.

<BR>

<BR></LI>

<LI><B>Date.</B> This tells when the message was sent, from the Date header of the message.

<BR>

<BR></LI>

<LI><B>Name.</B> This is the name of the person who sent the mail, from the From header. If no name is given, the Internet address of the person is used.

<BR>

<BR></LI>

<LI><B>Subject.</B> When the sender entered the message, his or her mail program asked for a message subject. It's shown here. If there's not enough room, the subject is truncated.

<BR>

<BR></LI>

<LI><B>Length.</B> This shows how large the message is. Here it's given in characters&#151;other programs give it in number of lines.

<BR>

<BR></LI></UL>

<H6 ALIGN="CENTER">

<CENTER>

<FONT SIZE=3><B>Reading New Messages</B>

<BR></FONT></CENTER></H6>

<P>All mail programs have a &quot;read new mail&quot; command. Usually, you use just r or press Enter. This shows you your new messages one at a time. When you're reading each message you have several options available, such as replying or deleting the 
message.

<BR></P>

<H6 ALIGN="CENTER">

<CENTER>

<FONT SIZE=3><B>Operating on Old Messages</B>

<BR></FONT></CENTER></H6>

<P>The same functions that are available when you're reading a message are usually available when you're not reading any particular message, and can apply to a single old message or to a group of them. As an example, when you're reading a message you can 
tell the mail program to delete the message. When you're not reading any messages you should be able to tell the mail program &quot;Delete message number 4&quot; or even &quot;Delete messages 4 through 6.&quot;

<BR></P>

<P>Messages are usually given by number, but if you're using a mail program that uses a mouse you may be able to select messages by clicking on them.

<BR></P>

<H6 ALIGN="CENTER">

<CENTER>

<FONT SIZE=3><B>Common Mail Functions</B>

<BR></FONT></CENTER></H6>

<P>Here's the standard list of mail functions you should learn how to do in your program:

<BR></P>

<UL>

<LI><B>Read message(s).</B> Obviously, if you can't do this, not much else matters.

<BR>

<BR></LI>

<LI><B>Delete message(s).</B> Mailboxes can become very cluttered with old mail and you can even &quot;lose&quot; important mail because it's so buried in junk. You need to be able to get rid of mail you don't care about.

<BR>

<BR></LI>

<LI><B>Flag message(s).</B> You should be able to flag messages as being important. The mail program should then make them stand out in some way so you remember to deal with them later.

<BR>

<BR></LI>

<LI><B>Send message.</B> You should be able to send mail to other people.

<BR>

<BR></LI>

<LI><B>Reply to message.</B> You should be able to easily send a response to the person who sent you a piece of mail, and include a portion of the sender's message text for reference.

<BR>

<BR></LI>

<LI><B>Save message(s) to file.</B> You'll probably get mail that contains important information you want to use in another program. You should be able to save the body of a message to file, which you can then manipulate at will.

<BR>

<BR></LI>

<LI><B>Switch to other mailbox.</B> If you start getting enough mail, you may find it handy to create other mailboxes. Perhaps one for the Bulgarian cooking mailing list of which you're a member. Your mail program should be able to handle several 
mailboxes.

<BR>

<BR></LI>

<LI><B>Move message(s) to other mailbox.</B> If you have multiple mailboxes, it should be possible to move mail from one to another.

<BR>

<BR></LI></UL>

<H6 ALIGN="CENTER">

<CENTER>

<FONT SIZE=3><B>Mail Configuration File</B>

<BR></FONT></CENTER></H6>

<P>Since how you handle your mail involves a lot of personal preference, almost all mail programs have many options that can be set. So that you don't have to set these every time you run your mail program, most mail programs have some sort of 
configuration file that is read every time the program starts.

<BR></P>

<P>You should definitely look into how to set this up for your mail program&#151;while doing so you will often find many options you didn't even know about. For instance, many programs will let you set aliases; for example, you can use just bill instead of 

wblowhard@longname.deep.stuff.edu. The mail program turns the alias into the full name.

<BR></P>

<H5 ALIGN="CENTER">

<CENTER><A ID="I21" NAME="I21">

<FONT SIZE=3><B>Common Mail Programs</B>

<BR></FONT></A></CENTER></H5>

<P>There are dozens of mail programs out there, and they can't all be covered here. Instead, this chapter touches on a few common ones.

<BR></P>

<H6 ALIGN="CENTER">

<CENTER>

<FONT SIZE=3><B>Mail (Berkeley Mail)</B>

<BR></FONT></CENTER></H6>

<P>Most UNIX boxes come with a simple program known just as mail, or as mailx. This is some variation on the mail program from Berkeley UNIX, so it's sometimes called Berkeley Mail. This program is minimal in functionality and presentation, but it works, 
and many people still use it. If you like mail I would recommend that you upgrade to mm90, which is discussed in the section, &quot;mm90 (Mail Manager 0.90).&quot;

<BR></P>

<P>mail has the capability of being used in a noninteractive mode. You can send a file to someone in this way:

<BR></P>

<PRE>mail -s &quot;subject&quot; recipient &lt; messagefile</PRE>

<P>Again, on some systems you need to use mailx. mail. recipient is who to send it to, subject is some message subject, and messagefile is the name of the file to send. You also can send the output of a program in a similar fashion:

<BR></P>

<PRE>program commands | mail -s &quot;subject&quot; recipient</PRE>

<P>You could instead save the output of the program to a file first, but why introduce an additional step if you don't need to?

<BR></P>

<H6 ALIGN="CENTER">

<CENTER>

<FONT SIZE=3><B>The Elm Mail System</B>

<BR></FONT></CENTER></H6>

<P>If you're the type of person who likes full-screen, menu-driven (and other hyphenated adjectives) interfaces, Elm might be up your alley. It was created as an easy-to-use UNIX mail program, but actually has a fair amount of configurability and power. 
The support programs that come with it might be worth getting on their own. And if you like printed manuals, it comes with over a hundred pages of documentation in PostScript format.

<BR></P>

<P>The Elm system is probably not standard on your system, so you'll have to get it yourself or beg your sysadmin for it. You can anonymous ftp it from ftp.uu.net under /networking/mail/elm, or from wuarchive.wustl.edu under /mirrors/elm. The packed source 

code is about a megabyte. You'll need to compile it and answer a few system configuration questions.

<BR></P>

<P>Messages are displayed in a format close to the &quot;standard&quot; one-message-per-line format described earlier, but now you can use your arrow keys to scroll about the messages and just press a key to inflict your wishes on the current message. The 

online help isn't bad&#151;just press ? at any time.

<BR></P>

<HR ALIGN=CENTER>

<NOTE>

<IMG SRC="imp.gif" WIDTH = 68 HEIGHT = 35><B>TIP:</B> Elm tip 1: Press o from the main menu to get the options screen. Press &gt; and Elm creates a file named .elm/elmrc&#151;this is a special options file that you can edit with vi or emacs (or whatever 
you use). Most of these options aren't easily set from inside Elm. Be sure to read the Ref.guide file for more information on these options.

<BR></NOTE>

<HR ALIGN=CENTER>

<HR ALIGN=CENTER>

<NOTE>

<IMG SRC="imp.gif" WIDTH = 68 HEIGHT = 35><B>TIP:</B> Elm tip 2: Elm can act as a command-line mailer just like Berkeley mail does&#151;it even uses the same syntax:

<BR>

<BR>elm -s &quot;subject&quot; recipient &lt; messagefile

<BR></NOTE>

<HR ALIGN=CENTER>

<HR ALIGN=CENTER>

<NOTE>

<IMG SRC="imp.gif" WIDTH = 68 HEIGHT = 35><B>TIP:</B> Elm tip 3: Don't ignore the support programs that come with Elm. A few of the most useful ones are the following: