This chapter covers the basic information on using electronic mail (e-mail) in the MMM computing environment.
E-mail is a facility for sending and receiving messages on computer networks. The Internet network allows you to communicate with people both locally and around the world who have computers connected to the Internet. Messages are often delivered within minutes, depending on the destination, and delivery is generally reliable, but not guaranteed.
Each user in MMM has both a UCAR e-mail address and a local MMM e-mail address.
Your UCAR e-mail address has the form
email@example.com user is your login name. Your UCAR e-mail address should be given to all correspondents outside of MMM; it is the most efficient and reliable address for general usage.
Your local MMM address has the form
firstname.lastname@example.orgYour MMM e-mail address is set up in the SCD gateway database when your account is created. Should you need to change it in the future, you will need to update this information in the SCD database. (See below for entering this information.)
Your e-mail messages will come in through the central email server and are then forwarded to the divisional mmm server. You must log on to a workstation to read this mail.
To change your e-mail address in the SCD database, enter
telnet directory login: directory A menu with options will appear. Select
(M) Modify UserYou will be prompted to enter your Scientist Number, SCD Login Name, and Project Number or gate keeper password.
Set "E-mail address" to
email@example.com user is your login name, host is the machine you want your mail to go to, and domain is the internet domain name. An example of a local MMM address is firstname.lastname@example.org.
On Unix systems, there is more than one program to read and send e-mail. The differences between these programs are mostly in the user interface. The standard Unix Mail utility for reading and sending messages has the advantage of being available on all Unix systems; its disadvantage is that it does not have a user interface that is very easy to learn or use.
elm is another mail utility that is distinguished by a user interface that is very easy to learn and use.
Netscape has a mail utility program which has a nice GUI interface. There is also a GUI Mail program available for the PCs and Macs called Eudora Pro. This document will discuss all five of these mail programs.
CTRL-c CTRL-c (Enter CTRL-c twice.) Cancels a message at any time. . Enter a .(dot) as the first character on a line and press RETURN to send a message. CTRL-d Alternate command to send a message.Alternatively, you can use a text editor to compose your message in a file, then read this message into the Mail utility.
When you use elm for the first time, it will ask you a set of questions, to which you should respond "yes". Once in elm, type o for a list of options to set up your configuration file, such as changing the default editor. We recommend that you change the User Level by selecting U. Change it to Intermediate User by pressing the space bar. This causes elm to give you an extended list of options in other menus. Once the Intermediate User option appears in the space, press RETURN. Press the > symbol to save these changes, then press i to return to the main menu.
Highlight "Identity" and enter your information using the example below:
|Your name:||Jody Williams|
|Signature file:||/users/tanner/.signature (if applicable)|
Note: A signature is a few lines of text that are automatically added to the end of an outgoing message when it is sent. It can be whatever you want, but it is usually used to give contact information (telephone, address, etc).
Now, highlight "Mail Servers" and enter your information using the example below:
|mail server username:||tanner|
|outgoing (SMTP) mail server:||mmm.mmm.ucar.edu|
|incoming mail server:||mmm.mmm.ucar.edu|
Highlight the incoming mail server mmm.mmm.ucar.edu, then click on the Edit button. On the General tab, Server name should be mmm.mmm.ucar.edu, and you should enter your username. Next Click on the POP tab and check "Leave messages on server." If you do not select this, all e-mail is copied to /users/username/nsmail.
To use the Netscape Mail program, start up Netscape then under the "Communicator" menu, choose "Messenger Mailbox"
The Address Book is used to set up aliases for individuals and groups. To access the Netscape Address Book, under the "Communicator" Menu, select "Address Book".
Filters will automatically take action on certain e-mail messages. To access Netscape filter options, within the Netscape mail window choose "Mail Filters" under the "Edit" menu.
If you need additional help with these and other Netscape features, there is an online help, under the "Help" menu, choose "Help Contents".
You have to provide basic information about your account, servers and network connection before you can send and receive messages. To do this, use the Getting Started Options which can be found under the "Tools" menu, "Options". Then enter your information using the example below:
|Getting Started:||POP Account:||email@example.com|
|Real Name:||Jody Williams|
|Personal Info:||POP Account:||firstname.lastname@example.org|
|Real Name:||Jody Williams|
|Checking Mail:||Check Mail every _ Minutes
Send on Check
Leave mail on Server
Delete from server after __ days
Delete from server when emptied from Trash
The other setup options include the following, but you do not need to edit these in order to set up Eudora. You may want to edit them to personalize your e-mail.
A signature is a few lines of text that are automatically added to the end of an outgoing message when it is sent. It can be whatever you want, but it is usually used to give contact information (telephone, address, etc). The signature feature can be found under the "Tools" menu.
The Address Book is where you keep information about individuals or groups that you correspond with. Each entry in the Address Book includes a nickname for a person or group, and their full e-mail address. You can also include their real name, contact information and notes. The Address Book can be accessed under the "Tools" menu.
Filters can be set up to take certain actions automatically on certain e-mail. For example, you can set up a filter to delete messages from specific senders or reply to messages or save them in mailboxes. Filters can be accessed under the "Tools" menu.
You can specify that a message be sent at a certain time in the future. Be careful using this option, because it is not always reliable.
If you need help setting up any of these features, please see the Eudora on-line help. Also, there is a Eudora Pro manual available in the MMM Computing Library.
If you are not running under X windows, or you do not want to hear beeps when mail arrives, you can run the program called newmail. When new mail arrives, a one-line message indicating the sender and subject will be displayed in the window where the program was started. You can start this program from within your .login file.
One program that you should not use is biff. This program will not work on our systems due to specifics of our cluster configuration.
alias programmers email@example.com firstname.lastname@example.org email@example.comIt is important to note that when entering aliases that contain more than one address, you must not enter a carriage return at the end of the lines of the alias definition. The definition should be one long "line" with a carriage return at the end.
The aliases that you insert in this file will be used whenever you send mail with the standard Unix mail command, or from within emacs. These aliases will not be seen by the elm program. If you send mail from elm, use the instructions below.
To send mail to an alias, simply use the alias name when elm prompts for the To: address. Remember that the elm aliases can only be used within elm; the Unix mail program will not see them.
The process detailed below will only respond to messages sent directly to you and will not respond to mailing list messages so you do not have to worry about the program sending messages when you receive mail addressed to mmmall or other such aliases. Also, the program keeps track of whom it has notified that you are away and will only send one such notification per 7 days. That is, if a user sends you mail on Monday and the vacation program replies and notifies that user that you are away and the same user sends you a message the next day, another notification will not be sent out. Only after 7 days have elapsed between the first and second messages (from the same sender) will another notification be sent out.
All your mail will be in its normal place and you can read it just like you usually do. The only difference is that people who send you mail are being notified that you're away.
The first time you use procmail for auto-replying to your email during your absence, their are several setup steps that need to be performed. This process will not be necessary on subsequent uses.
Setup of procmail for auto-reply
Set your default directory to your home directory
cd /users/login cp /usr/common/skel/.procmailrc . cp /usr/common/skel/.forward.vacation . mkdir .procmail[Note: If you are already using procmail for filtering, this directory already exists.]
cp /usr/common/skel/rc.rules.vacation .procmail/. mkdir /users/login/Mail [Note: This directory may already exist.]Next make the following modifications to the above files.
Change login to your login name
Change all instances of login to your login name
Next create the following file in /users/login/.procmail
cd /users/login/.procmail cat /dev/null > logUse of procmail auto-reply
Now that the necessary structure has been setup for procmail to auto-reply to incoming mail messages, take the following steps each time you will be away from your email.
cd /users/login/.procmail cp rc.rules.vacation rc.rules [Compose message to be sent to sender] vi /users/login/.procmail/vacation.msg or emacs /users/login/.procmail/vacation.msg cd /users/login cp /users/login/.forward.vacation .forward ALWAYS verify the setup is working by sending yourself on email before you leave. Note: On your return do the following:6.3.4 Sending Binary Files through E-Mail - uuencodemv /users/login/.forward .forward.vacation rm /users/login/Mail/vacation.cache
Sometimes it is necessary to send a binary (non-text) file through e-mail when ftp or another transfer program is not an option. E-mailing binary files should only be used as a last resort because (1) it is a non-trivial multi-step process, (2) mail was not designed as a file transfer mechanism, and (3) there is a limit on the size of e-mail that can be sent and received. The limit at NCAR is 200,000 bytes. If you are sending to an address outside of NCAR, they will have their own limit. Since binary files tend to be big, it can be impossible or cumbersome (see directions below) to send them via e-mail. Furthermore, the person you are sending the message to must be on a Unix system (or have access to one).
Assuming you have decided you must do this, here are the steps for sending the file. The binary file to be sent is called filename in the example below.
1. Save message to a file. In this example, it will be saved to
a file named mailfile.binary.
2. Type the command
4. You can now open filename within the appropriate application.
If you receive several messages that are parts of a single binary file, follow the receiving instructions for each message and then cat all the parts into a single file.
1. Using either elm or Berkeley mail, save the BinHex mail message
to a file (mailfile in this example).
2. Log on to a Sun system and execute the following command:
4. From a Macintosh, ftp the filename.bin from the Sun system using the
5. Fetch will convert filename.bin to filename. You can now
filename within the appropriate application.
Here's how it works:
Once opened in Netscape Navigator, the HTML file can be edited by clicking on "File", and choosing the "Edit Page" option.
NOTE:If you are going to use the procmail program, you are cautioned to be careful about the rules syntax. Incorrect syntax will prevent mail delivery to your account.
Create a .forward file in your home directory with the following line.
"|IFS=' ' && exec /usr/local/procmail/bin/procmail -f- || exit 75 #username"A configuration file, .procmailrc, needs to be created in the users home directory with the following entries.
#Set on when debugging VERBOSE=off #Replace `mail' with your mail directory (Pine uses mail, Elm uses Mail) MAILDIR=$HOME/mail #Directory for storing procmail log and rc files PMDIR=$HOME/.procmail LOGFILE=$PMDIR/log INCLUDERC=$PMDIR/rc.rulesA directory for procmail needs to be created off the users home directory.
mkdir ~/.procmailThis directory contains a log file and a filtering rules file.
ls ~/.procmail -rw------- 1 boydw users 8515 Nov 14 08:10 log -rw-r--r-- 1 boydw users 501 Nov 14 06:59 rc.rulesFollowing are samples entries in the rc.rules file
:0 * ^From:.*email-address /var/spool/mail/username :0 * ^X-Spam-Level: \*\*\*\*\*\*\*\* /dev/null :0 * ^X-Spam-Level: \*\*\*\*\* spam :0 * ^Subject:.*test folder :0 * ^Subject:.*TestScript | /users/username/script argThe above rules illustrate filtering based on an email's "From:", "X-Spam-Level:", and "Subject:" lines. When email comes in, the .forward file executes procmail using the rules in ~/.procmail/rc.rules. Procmail processes the rules sequentially, if a rule is true, the action is take, the transaction is logged to the file ~/.procmail/log and procmail exits. The following is an example of filtering email based on the subject line.
:0 * ^Subject:.*test folderA rule begins with ":0", followed by a line with an expression to match for example
* ^Subject:.*testmeans match a line that begins with "Subject:" followed by 0 to any number of characters, followed by the string "test", followed by any number of characters. The next line, "folder", is the action to be taken if there is a match, "folder" indicates that the email message will be copied to the file ~/mail/folder. The action may be piping the email message to a script. For example
:0 * ^Subject:.*TestScript | /users/username/script argsays if the subject line of an email messages contains the string "TestScript" pipe the message to the script "/users/username/script" with the argument "arg". The first three rules in the above rc.rules example filters spam.
:0 * ^From:.*email-address /var/spool/mail/username :0 * ^X-Spam-Level: \*\*\*\*\*\*\*\* /dev/null :0 * ^X-Spam-Level: \*\*\*\*\* spamThe first rule is used to copy any email coming from the address "email-address" to the users email file. It is placed before the two spam rules so it is processed first. Email coming from some addresses is falsely flagged as spam. This rule is used to make sure it goes to the users mail file. The next rule specifies that email with an "X-Spam-Level:" of more than 8 eight is thrown away. The next rule specifies that email with an "X-Spam-Level:" of 5 to 8 is copied to the file ~/mail/spam.
A. When sending files between machines at NCAR/UCAR, the size limit is 200,000 bytes. When sending to machines outside NCAR/UCAR, the limit is 65535 bytes.
Q. Can I retrieve deleted mail messages?
A. If you delete a message and are still in a mail utility, enter u to undelete the message. Once you exit mail, there is no mechanism for retrieving deleted messages.
Q. How can I tell if I sent a message to someone (or if it arrived)?
A. We do not and cannot record the delivery of every mail message sent from the division. If you are uncertain whether you sent a mail message, resend it. There is no mechanism to determine whether or not an individual has received a mail message.
Q. What if someone gave me an e-mail address and it does not work? I might have written it down wrong.
A. Usually it is hard to determine what the correct e-mail address should be. If it is very important and you think only a few characters might be wrong, a systems person can help in some cases. Usually, you must contact the individual in some other way to verify the address.
Q. Can I send binary files through mail?
A. In certain cases, binary files can be sent through mail, but it requires a special procedure.