Electronic mail may well be the most popular applications of online services,
and its usage is growing at a phenomenal rate.
Way back in 1994, BIS Strategic
Decisions (USA) forecasted over 25 billion email messages for the coming
year, more than twice the number for 1992. By one estimate, over a trillion
email messages were sent during 1996.
Oh, well.
Messaging Online reported 569
million email accounts globally at year-end 1999, up 83 percent on the previous
year. They predict there will be 1 billion email accounts in two years
time. In the early 1990s, there were 15 million email accounts in the world.
At the end of 2000, IDC Research estimated
that 10 billion emails were being sent every day.
If a given email service charges
you US$30 per hour, it will cost you a meager US$0.075 to send one typewritten
letter (size A-4, or around 2,200 characters). On the Internet, the cost
is almost negligible for many users. See Chapter 15
for a breakdown of this cost.
If you live in Norway, and
send the letter by ordinary mail to a recipient in Norway, postage alone
is US$0.52 (1994). The cost is seven times higher than when using email.
To send the same letter from
Norway to the United States by ordinary mail will cost 11 times more than
email. The letter takes several days to reach the destination, while email
messages arrive almost instantly.
Often, you can send email
messages to several recipients in one operation, and without paying extra
for the pleasure. Compare with what it costs to send to several parties using
fax!
You do not have to buy envelopes
and stamps, fold the sheet, put it into the envelope, and bring it to a mailbox.
Just let the computer call your favorite email service to send the letter.
The recipient does not have
to sit by the computer waiting for your mail. The message will be automatically
stored in his electronic mailbox. He can read it when he has time.
The recipient can print it
locally. It will be a perfect document, no different to one typed locally.
He can correct, make comments, and email it onwards to a third party. In
this way several people can work jointly on a report. There is never any
need for you to re-type the text from scratch.
When you receive several messages,
you can very quickly create replies to them one at the time at your keyboard,
and then send them in one go. No need to feed five different pieces of paper
into a fax machine or envelopes for five different people.
Where you can find a telephone,
you can also read mail. In most countries, communicating by email is easy
and economical.
The simple but miraculous
thing about email is that you can easily and exactly quote the point to which
you are replying. It is truly a revolution in communication.
Some online services have a limit on the size of your mailbox. If you
receive a lot of mail, you must regularly read and make room for new. If
your mailbox is full, new mail may be rejected without warning. You may never
know that a person tried to reach you. Select a service that has room for
all your mail!
How to send email?
Many users just "talk" with an email program to send and receive mail. Internet
users of programs like Pegasus Mail and Eudora typically compose mail
before calling the access service. They click on a "write new mail"
icon, enter an email address, a subject, write the text, and click at Send.
When all outgoing messages
have been composed, they logon to the Internet. Their mail is sent in one
batch, and incoming messages are retrieved. The interaction with the online
service is transparent to the user. Simple. Safe. Quick. Cheap. (see
Chapter 16 for more on automatic email programs).
CompuServe users of programs
like OzWin or TAPCIS do it in a similar way, but they can also do it manually.
Other systems require different commands to send email.
The Login host in Oslo (Norway)
is a Unix system connected to the Internet. So is The
Well in San Francisco. On these systems,
mail may be sent using the following type of commands:
-
Type "mail presno@eunet.no".
-
When the computer asks for "Subject:," enter "Hello, my
friend!"
-
Type your message, or send a pre-prepared text.
-
When done, enter a period (.) in the beginning of a line, and the message
is on its way.
Though the commands for sending email differ between systems, the principle
is the same. All systems will ask you for an address, and the text of your
message. On some, the address is a code, on others a name (like ODD DE PRESNO).
The same applies to the email programs.
Most systems and programs
will ask for a Subject title. Many will let you send copies of your mail
to other recipients (Cc:).
Some services let you send
binary files as email. Binary files contain codes based on the binary numeration
system. Such codes are used in computer programs, graphics pictures, compressed
spreadsheets, word processed text files, and sound files.
Mail through the Internet
Internet's core network has gateways for electronic mail to systems on many
other networks. When we include these systems and their connections, we call
it the Matrix, or WorldNet (see Appendix 1 for more).
If you read this handbook,
you probably already have access to the net. If you want to check your options,
take a look at the links in the "Services offering access
to Internet" appendix.
If you are on the Matrix,
you can send email to users on networks like EUnet, JANET, Uninett, BITNET,
UUCP, CompuServe, MCI Mail, EcoNet, PeaceNet, ConflicNet, GreenNet, Web,
Pegasus, AppleLink, Alternex, Nicarao, UUNET, FredsNaetet, PSI, Usenet, FidoNet
and many others. You can send to people using Bergen By Byte in Norway,
TWICS in Tokyo, and Colnet in Buenos Aires.
When people talk about this
phenomenon, they often refer to it as "Internet mail," even if they are just
using the Internet as kind of an advanced telephone exchange.
Let us take a closer look
at the art of addressing mail through the Internet and the Matrix.
Domain name addressing
On the Internet, the general form of a person's email address is:
user-name@somewhere.domain
My main, international Internet mailbox address is:
presno@eunet.no
Read the address from left to right. First, the local name of the mailbox
(my name abbreviated). Next, the name of the mailbox system or another
identification code (here Login), the name of the institution or company
(here EUnet, a Norwegian Internet provider), and finally the country (NO
for Norway).
People have sent mail to my
mailbox from New Zealand, Zimbabwe, Guatemala, Peru, India, China, Greece,
Iceland, and Armenia using this address.
Some of them had to send their
mail through a gateway to the Internet, and the address sometimes had to
be changed accordingly:
Users of AppleLink use
presno@eunet.no@INTERNET# . Those on JANET use
presno%login.eunet.no@eanrelay.ac.uk. On SprintMail, use ("RFC-822":
<presno(a)login.eunet.no>, SITE:INTERNET) . CompuServe subscribers
use INTERNET:presno@eunet.no .
The core of these address
formats is "presno@eunet.no," in one way or the other.
We call the core addressing
format a Domain Naming System. "LOGIN.EUNET.NO" is a domain. The domain may
also contain reference to the name of a company or an organization, like
in twics.co.jp, compuserve.com, or IGC.ORG. The CO, COM, and ORG codes identify
TWICS, CompuServe and IGC as companies or
organizations.
To send mail from the Internet
to my CompuServe mailbox, use (do not expect a fast reply!):
75755.1327@compuserve.com
Normally (except on AppleLink), a domain address can only contain one @-
character. When an address has to be extended with gateway routing information,
replace all @-characters to the LEFT in the address by %- characters. Here
is an example:
BITNET uses a different addressing
method (USER@SYSTEM). On some Internet systems, you can simply use the address:
USER@SYSTEM.BITNET , and the email system will handle the routing for you.
If this method doesn't work,
you may use a gateway into BITNET. You may route through CUNYVM.CUNY.EDU
by composing an address like this:
USER%SYSTEM.BITNET@CUNYVM.CUNY.EDU
The rightmost @ in this address is maintained. The one to the LEFT has been
replaced with a %. The term ".BITNET" tells the gateway machine where to
forward the message.
The following will happen:
First, the message will be sent to system CUNYVM at the EDUcation site CUNY.
CUNYVM investigates the address, and discovers that the message is for BITNET.
It cuts off all text to the right of "USER," and replaces the % with an @.
The message is forwarded to the mailbox USER on the BITNET system SYSTEM.
Replace USER and SYSTEM with real addressing data.
How to get a personalized domain name?
If you're a small business,
you may like to have a personalized domain name like the big ones. Microsoft
uses microsoft.com, IBM uses ibm.com, HotBot uses
hotbot.com, and it sure would be nice to have your own
yourname.com. The only problem is the cost...
For cost-efficient ways
of getting a personalized domain name, check out the
email-for-free services. USA.NET is
one vendor.
Things Take Time!
How long does it take a message to get from Hyougo in Japan to Saltrod in
Norway? To Dominique Christian in Paris?
Sometimes, mail travels from
mailbox service to mailbox service in seconds. This is usually the case with
messages from my mailbox in Norway to Dan Wheeler in Ohio (U.S.A.) and Mike
Burleigh in London.
Messages that must go through
many gateways may take more time. How long it takes, depends on the degree
of automation in the mail systems involved, and how these systems have been
connected to the global matrix of networks.
Speed is high if the computers
are interconnected with fixed, high-capacity lines. This is not so for mail
from Oslo to Dominique in Paris. Although the distance is not great, mail
is routed through a system in London and is forwarded only once a day through
a dial-up connection. It usually takes at least one day to reach the destination.
Returned mail
Once you have learned the basics of Internet mail, it is relatively easy.
However, be ready for some glitches and hiccups based on incompatibilities
between different email systems and gateways, differences in protocols, clients,
etc. While this is not an "Internet problem" by itself, it will look like
one.
Returned mail is one of the
results. When an email address is incorrect in some way (the system's name
is wrong, the domain doesn't exist, whatever), the mail system will bounce
(route) the message back to the sender. This will also happen if the receiver's
mailbox is full.
The returned message will
include the reason for the bounce.
The most common error is
addressing mail to a non-existent account name or network address. For example,
I have seen many users trying to send mail to LISTSERV@VM1.NODAK.EDU using
LISTSERV@VML.NODAK.EDU. When written in lower case letters, it is easy to
think that the number "1" in the address is the letter "l". Alas, the result
is an error message.
Let us construct an error
when sending to LISTSERV@VM1.NODAK.EDU. Send a mail to "pistserv@VM1.NODAK.EDU".
This address is wrong. Below,
you will find the full text of the bounced message. It contains much technical
information, and most lines have no interest. Also, the message is much larger
than the original message, which contained three lines only.
When browsing the bounced
message, note that it has three distinct parts: (1) The mailer header of
the bounced message itself (here, the 13 first lines), (2) The text of the
error report (from line 14 until the line "Original message follows:"), and
(3) the mailer header and text of your original message (as received by computer
reporting the error):
From MAILER@VM1.NoDak.EDU Fri Dec 18 12:54:03 1992
Return-Path: <MAILER@VM1.NoDak.EDU>
Received: from vm1.NoDak.edu by pat.uio.no with SMTP (PP)
id <07610-0@pat.uio.no>; Fri, 18 Dec 1992 12:53:54 +0100
Received: from NDSUVM1.BITNET by VM1.NoDak.EDU (IBM VM SMTP V2R2)
with BSMTP id 9295; Fri, 18 Dec 92 05:53:27 CST
Received: from NDSUVM1.BITNET by NDSUVM1.BITNET (Mailer R2.07)
with BSMTP id 3309; Fri, 18 Dec 92 05:53:26 CST
Date: Fri, 18 Dec 92 05:53:26 CST
From: Network Mailer <MAILER@VM1.NoDak.EDU>
To: presno@eunet.no
Subject: mail delivery error
Status: R
Batch SMTP transaction log follows:
220 NDSUVM1.BITNET Columbia MAILER R2.07 BSMTP service ready.
050 HELO NDSUVM1
250 NDSUVM1.BITNET Hello NDSUVM1
050 MAIL FROM:<presno@eunet.no>
250 <presno@eunet.no>... sender OK.
050 RCPT TO:<pistserv@NDSUVM1>
250 <pistserv@NDSUVM1>... recipient OK.
050 DATA
354 Start mail input. End with <crlf>.<crlf>
554-Mail not delivered to some or all recipients:
554 No such local user: PISTSERV
050 QUIT
221 NDSUVM1.BITNET Columbia MAILER BSMTP service done.
Original message follows:
Received: from NDSUVM1 by NDSUVM1.BITNET
(Mailer R2.07) with BSMTP id 3308;
Fri, 18 Dec 92 05:53:25 CST
Received: from pat.uio.no by VM1.NoDak.EDU
(IBM VM SMTP V2R2) with TCP;
Fri, 18 Dec 92 05:53:23 CST
Received: from ulrik.uio.no by pat.uio.no with local-SMTP (PP)
id <07590-0@pat.uio.no>; Fri, 18 Dec 1992 12:53:24 +0100
Received: by ulrik.uio.no ; Fri, 18 Dec 1992 12:53:18 +0100
Date: Fri, 18 Dec 1992 12:53:18 +0100
From: presno@eunet.no
Message-Id: <9212181153.AAulrik20516@ulrik.uio.no>
To: pistserv@VM1.NODAK.EDU
Subject: test
index kidlink
The first part of the bounced message is usually of no interest. Hidden in
the second part, you will find the following interesting line:
554 No such local user: PISTSERV
Ah, a typo!
If your original message was long, you are likely to be pleased by having
the complete text returned in the third part of the bounced message. This
may allow you to get away with a quick cut and paste, before resending to
the corrected address.
The text and codes used in
bounced messages vary depending on what type of mailbox system you are using,
and the type of system that is bouncing your mail.
Above, MAILER@VM1.NoDak.EDU
returned the full text of my bounced mail. Some systems just send the beginning
of your original text, while others (in particular some X.400 systems) just
send a short note telling the reason for the bounce.
Note: If you don't understand why a message bounces, contact your
local postmaster for help. Send him a copy of the full text of the bounced
message up to - and including - the line "Subject:" at the bottom. (There
is no need to send him the TEXT of your original message! Just the header
information.)
Returned due to error in contents
When you write a message to a real person, you are usually free to format
the text any way you want. However, not so when the recipient is a computer
program, like a LISTSERV, Gophermail, or a World Wide Web by email server.
Example: This book is being
updated regularly. Information about where to find the electronic version
can be retrieved by sending an email to
listserv@listserv.nodak.edu.
Put the command "GET TOW.WHERE" in the body of your mail.
Type in this command starting
in your mail's line 1, column 1, If the text starts with something else,
chances are that you will get an error message rather than the requested
information.
Many users access the Internet
through gateways from a company's internal mail system, and some of these
mailers insist on adding extra information to the text, like in this Swedish
example:
Microsoft Mail v3.0 IPM.Microsoft Mail.Note
Fr}n: Johan Svensson
Till: TOW
Ang}ende: Message headers
Datum: 1994-07-23 19:39
Prioritet:
Brev-ID: FE0257B9
Konversation-ID: FE0257B9
If the mail system's administrator is unable or unwilling to let you send
Internet mail without such extra headers, then you have problems. To get
around it, check if it is possible to send your message as a file.
Replying to an Internet message
On the Internet, electronic messages have a common structure that is common
across the network. On some systems, you can reply by using a reply command.
If this feature is not available, use the sender's address as given in the
mail header.
The bounced message contained
two mail headers: the header of my original message (in part three), and
the header of the bounced message (in part one).
The 'good' reply address is
laid out in the 'From:' header. Thus, this message contains the following
two 'good' addresses:
From: Network Mailer <MAILER@VM1.NoDak.EDU>
From: presno@eunet.no
The Network Mailer located the second address line in my original message,
and used this address when sending the bounced message.
Note: there is no point in sending a message back to MAILER@VM1.NoDak.EDU
since this is the address of an automatic mail handling program. Write to
Postmaster@VM1.NoDak.EDU to talk to a "real person" at this computer center.
The exact order of a message's header may vary from system to system, but
it will always contain the vital 'From:' line.
Note: Exercise caution when replying to a message sent by a mailing
list. If you wish to respond to the author only, make sure that the only
address you are replying to is that person's. Do not send it to the entire
list!
How do I know my message is received?
On some networks, it is outright impossible. On others, you can require that
an automatic acknowledgement be returned, when your mail has been received.
On the Internet, users can
often have their mailer add the Return-Receipt- To: <sender's email
address> line to the mail headers.
Replace "sender's email address" with your real address.
Some mailers allow users to automate this. The final MTA (message transfer
agent) will then send a "received" receipt to the specified address.
Changing your email address
If you change your email address for any reason, you must take steps to ensure
continued delivery of mail to your new address:
-
Before cancelling your old account, send a change of address message to all
your regular correspondents. There are two reasons for this:
-
Some recipients use the filtering features of their email programs to block
mail from unwanted addresses, and this may include all unknown people. Write
immediately to make sure your mails are not discarded, or land among all
the other mails "to be read later, when I get time."
-
Maintaining two email accounts simultaneously, even for a short transitional
period, may be a hassle - unless you use an email program that can deal with
several accounts automatically (like Eudora Pro).
Note: If you maintain two email accounts simultaneously, it is very
important that all new mail originates from your new address! So that
people can send reply messages to the correct address.
-
Consider sending the change of address message at three different times:
-
As soon as your new account is operational.
-
A reminder to anyone who sends mail to your old address during the transition
period..
-
At the end of the transition period.
-
Attach a change of address message to your customized signature file (if
you use one) at the end of all email that you send.
-
Before you cancel your old account, change your subscription to any automated
mailing lists in accordance with the list's particular instructions.
-
Use your old account to send the SIGNOFF command to unsubscribe
from the list. This will save you a lot of trouble. If it is too late, then
you may have to write to the moderator of the list and ask her to sign you
off manually on your behalf.
-
Use your new account to resubscribe to the mailing list.
-
Since some of the people who might want to send you email will not receive
your change-of-address message, make sure that email address directories
contain your new address.
-
Make sure that all web pages that contain your email address are being updated.
If you are maintaining web pages, and have your email at the bottom of the
page, don't forget that these entries must also be updated.
-
If you have ever sent a message to a Usenet newsgroup, send another one (to
any newsgroup). This will add your new address to databases being used to
find Internet user addresses.
Changing your email address is bothersome, so some users prefer to hunt for
a permanent email address. The traditional means is to reserve your own domain
name. Once done, your email address can move to whatever Internet server
hosts your domain.
A cheaper alternative is provided
by mail-forwarding services like
Pobox and
NetBox. An even greater bargain
may be the services providing email for free..
Email for free
May services on the Internet will let you do email for free - or almost free
- in exchange for the right to put an advertisement on every page you read.
Here's some popular US providers:
Hotmail ,
USA.NET ,
RocketMail,
MailCity ,
Juno,
MailExcite,
iName.
They simply let you read your
mail using a standard web browser. All you need is a computer hooked to the
Internet and access to the web. You may find it at a library, at school,
at work, on an airport, an Internet cafe. Anywhere. You get email without
having to pay for an account with an Internet Service provider!
HushMail uses a Java applet
to encrypt (with 1,024-bit encryption) and decrypt messages sent between
users with HushMail accounts.
Hint: Most of these
services require that you must be connected to the net while reading and
replying . Those accessing the Internet using a dial-up modem, may find this
expensive. Note that Outlook Express as of version 5.0 allows you to read
and reply to mail offline ("web mail"). You dial up to send and receive mail,
then hang up your phone. Read and reply at your own pace, and then reconnect
to send and check new mail when ready.
If you insist on using a service
where you must be connected to the net while reading and replying, select
an international service if your main application is use while travelling
abroad. Else, you will find it cheaper and easier to use a local service.
To find a service, try the
Free Email Providers Guide.
Using two or more mailboxes
Many users have one mailbox for work and one or several mailboses for private
use. Often, these resides on different Internet Service Providers' (ISPs)
machines.
Modern email software, like
Outlook Express and Eudora, let you automatically check mail in all mailboxes
in one go. All it takes is to dial into the net through one of your ISPs,
and hit "Check new mail." You do not have to dial up each ISP individually.
While retrieving mail like
this is easy, special attention must be paid to how you send mail. If you
set the properties for your second email account as instructed by your ISP,
you risk receiving error messages saying "Relay not permitted." This
happens when an ISP (quite commonly) refuses to send mail from you if you
are logged on to a different ISP. Only messages logged on to the ISP that
owns the server will be allowed through. They do this to prevent nonsubscribers
from using their servers.
The way around this problem
is to specifiy in the Properties dialog for the second email account that
it is to use the first account's outgoing server (smtp server). (In
Outlook Express, do this in Tools|Accounts|Properties.)
Example: Usually, I use four
different mailboxes for outgoing mail. When at home, I might be sending all
mail from all mailboxes through the smtp server of the Tele2 ISP. When
travelling, I often change to the smtp server of my Eunet Traveller account.
Thus, the mail you receive
from presno@eunet.no might have been sent from the Tele2 server. This fact
will be recorded in the small details of the mailer header of my mail to
you.
Warning: This is possible
because outgoing mail servers (SMTP) usually do not ask you to identify yourself
by password to send mail. This means that you can send mail from a fake address,
like Michael.Jackson@heavens.org. Furthermore, it means that others can send
mail using your name. So, if in doubt about mail you're receiving, check
the mailer header to see where it comes from. If it comes from a different
server, return a request for confirmation. As receipt of mail is password
protected, the fake sender will not be able to reply.
The Traveller's Dream
The email-for-free services may appear to be the traveller's dream. They
let you get to your email while travelling without the hassle of finding
a local access point for your Internet provider, or buying from a local service.
An even better solution is
MailStart. Like the email-for-free
services, everything is done using Web browser. Enter your email address
(as in "presno@eunet.no"), and your login password (the one you normally
use to get your mail when at home). MailStart will get your mail for you,
and let you handle it in a safe way.
The advantage is that you
do not have to be concerned about using several email addresses for your
mail. The effect is that replies to your mails will go to your main account,
and not to an account that you may forget to check for incoming mail later.
Xmail is a good alternative.
Bang addressing
"Bang" is American for "exclamation point" (!). The UUCP network uses it
in their variation of the domain addressing scheme.
Example: User Jill Small on
Econet in San Francisco used to have the address pyramid!cdp!jsmall . Read
this address from right to left. The name of her mailbox is to the right.
The name of the organization is in the middle. "Pyramid" is the name of the
network.
Note: The ! character has a special function on Unix computers. You
may have to type the address as pyramid\!cdp\!jsmall to avoid unwanted error
messages. The \ character tells Unix to regard the next character as a character,
and not as a system command. You can also precede other problematic characters
with \ in case of problems.
Some email systems can use bang addresses directly. If your system is unable
to handle them, then you must send these messages through a gateway. The
American host UUNET is a frequently used gateway. If routing through UUNET,
you may write the address like this:
pyramid!cdp!jsmall@uunet.uu.net
If your system refuses to accept exclamation points in addresses, try converting
the address into a standard Internet address. Write the address elements
in the Internet sequence (left to right). Replace the exclamation points
with %-s, like this:
jsmall%cdp%pyramid@uunet.uu.net
This method works most of the time. If it works, use this addressing form.
Bang paths may fail if an intermediate site in the path happens to be down.
(Most UUCP sites are registering Internet domain names now. This helps lessen
the problem of path failures.)
Some messages must be routed through many gateways to reach their destination.
This is the longest address that I have used:
hpda!hplabs!hpscdc!hp-lsd.cos.hp.com!oldcolo!dave@uunet.uu.net
It used to be the address of a user in Colorado, U.S.A.. Today, he can be
reached using a much shorter address.
If you are on UUCP/EUnet,
you may use the following address to send email to Odd de Presno:
eunet.no!presno
Addressing international electronic mail sometimes looks like black magic.
To learn more, read some of the books listed in Appendix
5.
cc:Mail gateways
Many Local Area Networks have been connected to the global Matrix of networks.
CompuServe offers a cc:Mail gateway. Lotus cc:Mail is a PC Lan based email
system used in corporate, government and other organizations.
When sending from CompuServe
Mail to a cc:Mail user through this gateway, a typical address may look like
this:
>mhs:pt-support@performa
To send to this user from the Internet through CompuServe's MHS gateway,
write the address like this:
pt-support@performa.mhs.compuserve.com
Other vendors of LAN gateways use different addressing methods.
Email to Fax
Many online services let you send your messages to millions of fax machines,
as telex (to over 1.8 million telex machines), and as ordinary paper mail.
We have tested this successfully on CompuServe,
MCI Mail and other services.
On CompuServe, replace "Odd
de Presno 75755,1327" with "FAX: 4737027111". My fax number is +47 370 27111.
On MCI Mail type "CREATE:".
MCI asks for "To:," and you type "Odd de Presno (Fax)." MCI asks for "Country:".
You enter "Norway". By "RECIPIENT FAX NO" enter "37027111" (the code for
international calls). The country code for Norway, 01147, is added automatically.
By "Options?," press ENTER. When MCI Mail asks for more recipients, press
ENTER. Type your message, and have it sent.
Some commercial services let
you send faxes worldwide from the Internet. Examples:
FAXiNET (Also
handles inbound addresses), and
InterFax.
The FAQ
"How can I send a fax from the
Internet?" is posted regularly to
alt.internet.services,
alt.online-service,
alt.bbs.internet,
alt.answers and
news.answers on Usenet.
Email to Telex
To send a telex, you'll need the recipient's telex number, an answerback
code, and the code of the recipient's country. If the message is meant for
telex number 871161147, answerback ZETO, and country Russia (country code
871), enter "TLX:871161147 ZETO" when sending from CompuServe.
When the recipient is using another mailbox system
When the recipient is using your mailbox service, writing addresses is simple.
Not so when your email has to be forwarded to mailboxes on other online services
through the Internet, X.400, or similar.
A typical inter-system email
address consists of a user name, a mailbox system code, and sometimes also
routing information. The problem is that there is no universal addressing
format. Finding out how to write a given address may be surprisingly difficult.
Some services are not set
up for exchange of email with other services.
If your favorite system lets
you send mail to other services, make a note about the following:
-
You need to know the exact address of your recipient, and whether he is using
this mailbox regularly. Many users have mailboxes that they use rarely or
never. Also, think of the easiest way for a recipient to respond before sending
a message to him or her.
-
You may need to know how to rewrite the recipient's address to fit your system.
For example, you may have to use a domain address to send through Internet,
and a different form when sending through an X.400 network. (More about this
later.)
-
The recipient's mailbox system may not be on a network that has an email
exchange agreement with your system's network(s). Sometimes, you may have
to use a commercial email relay service to get your mail across (see
Chapter 9).
-
You may need to know how to route a message through other systems to arrive
at its destination. For example, mail from the Ulrik computer in Oslo for
Dominique Christian on the Difer system in Paris (France) used to be routed
through a center in London.
-
Example: If you have problems sending email to me at the address presno@eunet.no,
then you may succeed by rewriting it as presno%login.eunet.no@listserv.nodak.edu
. The message will then go to listserv.nodak.edu, which will turn it into
presno@eunet.no and forward it there. (More under Domain Name addressing
below.)
-
While it may be easy to enclose binary files when sending to someone on your
system, this may be impossible when sending across mailbox system boundaries.
-
While it may be possible to send text containing embedded control codes and
special language characters to users of your system, they may disappear when
sent to people elsewhere. Your safest bet is to send your text as standard
7-bit ASCII text (see Appendix 4).
-
It is the lowest common denominator between computers, software, networks,
and users.
-
Example: A user in Norway tried to send the Norwegian language line: "Jeg
bor på Karlsøy i Troms, Norge." The text was stored using Windows
Latin1. The receiver got: "Jeg bor pe Kalsxy i Troms, Norge." Another user
received the word "på" as "p=E5."
-
If you are using WordPerfect or Word for Windows on an MS-DOS computer, consider
storing your text as DOS text before sending.
X.400 addressing
X.400 is a standard for electronic mail developed by ITU-TSS. It is used
on large networks like AT&T Mail, MCI Mail, Sprintnet, GE Information
System, Dialcom, and Western Union, and on public and private networks throughout
the world.
EDI (Electronic Data Interchange)
uses X.400 as a transport mechanism for coordination of electronic part ordering,
stock control and payment. X.400 is used to connect EDI systems between companies
and suppliers.
The X.400 addressing syntax
is very different from domain addressing. To send a message from an X.400
mailbox to my address (presno@eunet.no), you may have to write it like this:
(C:NO,ADMD:uninett,PRMD:uninett,O:eunet,OU:login,S:presno)
Alas, it's not so standard as the domain addressing schemes. On other X.400
networks, the address must be written in one of the following formats - or
in yet other ways:
(C:US,A:Telemail,P:Internet,"RFC-822":<presno(a)login.eunet.no>) |
("RFC-822": <presno(a)login.eunet.no>, SITE:INTERNET) |
'(C:USA,A:TELEMAIL,P:INTERNET,"RFC-822":<presno<a>login.eunet.no>)
DEL' |
(site: INTERNET,ID:
<presno<a>login.eunet.no>) |
"RFC-822=presno(a)login.eunet.no @
GATEWAY]INTERNET/TELEMAIL/US" |
S=presno/OU=login/ORG=eunet/P=uninett/C=no |
To send from the Internet to a mailbox I once had on a Norwegian X.400 host
(Telemax), I had to use this address:
/I=D/G=ODD/S=PRESNO/O=KUD.DATASEKR/@PCMAX.telemax.no
To send from the Internet to Telemail in the US, I have used this (on one
long line):
/PN=TELEMAIL.T.SUPPORT/O=TELENET.MAIL/ADMD
=TELEMAIL/C=US/@sprint.com
If must route your message through gateways, then complexity increases. One
Norwegian UUCP user had to use the following address to get through to me
(on one long line):
nuug!extern.uio.no!"pcmax.telemax.no!
/I=D/G=ODD/S=PRESNO/O=KUD.DATASEKR/"
To send from an X.400 system to my CompuServe mailbox, I have used the following
address elements:
Country = US
ADMD = CompuServe
PRMD = CSMail
DDA = 75755.1327
The addressing methods used on X.400 systems vary. Example: Some use the
code C:USA rather than the ISO country code C:US. MCI Mail uses C:NORWAY,
C:USA, and C:SWEDEN.
Here are some important X.400 codes:
C |
|
the ISO country code (on most services) |
ADMD |
|
domain code for public system (abbreviation A) |
PRMD |
|
domain code for connected private system (abbreviation P) |
O |
|
organization name |
OU |
|
organization unit |
S |
|
surname (last name) |
G |
|
given name (first name) |
I |
|
initials (in the name) |
DDA |
|
domain-defined attributes, keywords defined and used by the individual
systems to specify mailboxes (user name, list, station, user code, etc.),
direct delivery devices (attention name, telex addresses, facsimile,
etc.) |
PN |
|
personal name |
(a) |
|
the character @ cannot be used when routing messages
from X.400 to Internet. Try (a) instead. |
(p) |
|
the character % cannot be used when routing messages
from X.400 to Internet. Try (p) instead. |
(b) |
|
the character ! (used in "bang" addresses). |
(q) |
|
the character " used in email addresses. |
RFC-822 |
|
this code tells X.400 that an Internet domain address follows.
Does not work on all X.400 systems. (See
http://info.internet.isi.edu/in-notes/rfc/files/rfc822.txt)
|
> The space character (ascii 032) is a special challenge. Some services
let you replace it with an '_' character. If the X.400 gateway supports MIME,
you may be able to use the hexadecimal code (=20) as specified in RFC1341
(see "quoted-printable"). If you do, remember to replace the '=' character
with =3D, as in '/S=3DPRESNO' (instead of '/S=PRESNO').
Addressing mail from the Internet
to/from X.400 is difficult, unless the mailer header of a received message
gives the senders address in the proper addressing format.
To set up an email link between
an Internet and an X.400 mailbox, start by trying to send an email from either
mailbox to the other. If one of them succeeds, then the mailer header of
the received message may explain how to send a reply.
Example: This is a typical
Internet mailer header on a message received from an X.400 service:
From MSGSUPPORT@smc-tm22.sprint.com Thu Oct 27 02:44:55 1994
Return-Path: <MSGSUPPORT@smc-tm22.sprint.com>
Received: from sprintf.merit.edu (sprint.com) by grida.no with SMTP
id <AA02280>; Thu, 27
Oct 1994 02:44:52 +0100
Received: from sprint.com by sprintf.merit.edu (8.6.5/merit-1.0)
id VAA01624; Wed, 26 Oct 1994
21:45:12 -0400
X400-Received: by mta merit in /PRMD=internet/ADMD=telemail/C=US/;
Relayed; Wed, 26 Oct 1994
21:44:54 -0400
X400-Received: by /ADMD=TELEMAIL/C=US/; Relayed; Wed, 26 Oct 1994
21:41:29 -0400
Date: Wed, 26 Oct 1994 21:41:29 -0400
X400-Originator: MSGSUPPORT@smc-tm22.sprint.com
X400-Recipients: non-disclosure:;
X400-Mts-Identifier: [/ADMD=TELEMAIL/C=US/;UGJE-6721-7167/27]
X400-Content-Type: P2-1984 (2)
Content-Identifier: VL72373 27
From: MSGSUPPORT@smc-tm22.sprint.com
Message-Id: <UGJE-6721- 7167/27*/S=MSGSUPPORT/O=
SMC.MSG.TM22/ADMD=TELEMAIL/C=US/@MHS>
To: PRESNO@GRIDA.NO
Subject: RE: HELP
Here, it is simple. Both the Return-Path line and the From: line have the
correct Internet address.
If the mailer header does
not contain such information, converting the X.400 addresses into a RFC-822
addresses may well be regarded as a black art. Also, note that you cannot
send email from the Internet to all X.400 users on the globe. Some gateways
are only accessible from commercial services.
For example, continued attempts
to send from an Internet mailbox in Norway to an X.400 address in a Nigerian
company failed, while mail to/from CompuServe worked
well.
Privacy
The level of online privacy differs by network, service, and application.
Whatever these services may claim, always expect that someone, somewhere,
can watch, even record.
All mailbox services have
at least one person authorized to access your personal mailbox in case of
an emergency. Most of the time they do not have a right to read it without
your permission, but they can.
In some countries, mailbox
services may let outsiders (like the police) routinely read your private
email to check for 'illegal' contents. Here, email is not safer than ordinary
mail.
The good news is that most
'inspectors' and 'sysops' are good, honest people. On the other hand, it
is useful to know your situation.
It is not safe to send
sensitive information (like credit card details) by private electronic mail.
True, the chance of an outsider getting hold of and take advantage of such
information is very small, but it is not safe.
On the Internet, it is child's
play for some people to intercept your mail. The typical email message travels
through many computers. At each computer, people can access your personal
and business correspondence.
However, with so much mail
traveling the network, it is highly unlikely that they will, but they
can.
Encrypt your email to protect sensitive information. Encryption also
guarantees the identity of the sender of a message, a most useful attribute
when financial transactions are involved.
The PGP (Pretty Good Privacy) software
has become the Internet standard for encryption of email and files so snoops
cannot read them. For more information on encryption, check
http://world.std.com/~franl
http://www.isoc.org/internet/issues/encrypton/
http://www.chem.swin.edu.au/~graeme/pgp.html
Sometimes, we need to be certain that a message was written by the sender
quoted in the mail's message header. As it is child's play to send an Internet
message carrying other people's return email address and name, you may want
to use PGP to make sure the correspondence is authentic.
For this reason, be very skeptical
if you ever get a message purportedly from your Internet access provider
telling you to change your password to "k00l/d00d!"
Privacy is also a concern
when talking in the open. Always assume that someone is recording all that
is being said in online conferences, chats, and other interactive social
gatherings. In chats, anyone using a personal computer as a terminal can
log the conversation, or use screen dump to capture 'interesting parts'.
Many PC users can scroll back
the screen. They can wait and decide whether to save the conversation in
a file until after the conversation has taken place. With these capabilities
widely available, users of chats and talk should always assume that their
conversations are being recorded.
Do not say indiscreet things
in small, informal discussions. Others may record and repost it under
embarrassing circumstances. An unauthorized forward of your private
correspondence is extremely easy, and completely outside your control!
Some people routinely use
anonymous remailers when sending email to Usenet newsgroups or persons to
make sure that the recipient (and snoops) cannot tell their real name or
email address. I never use these services, but note that some do as you may
be at the receiving end. For more on anonymous mail, check out the
alt.privacy.anon-server newsgroup.
The files RFC 1113 through
1115 are about 'Privacy enhancements for Internet electronic mail' (Available
from
http://www.rfc-editor.org/rfc.html)
Usenet has
alt.privacy (Privacy issues in cyberspace),
alt.security.pgp,
comp.society.privacy,
comp.security.pgp.announce,
comp.security.pgp.tech,
comp.security.pgp.discuss,
comp.security.pgp.resources,
and more.
Email: When everything fails
Data communications is simple - when you master it. Occasionally, however,
you WILL lose data. You may even experience the worst of all: losing unread
mail on your hard disk.
A while ago, this happened
to my sister. She logged on to her mailbox service using the communications
program Procomm.
After capturing all her mail,
she tried to send a message. For some reason, the computer froze. It was
impossible to close the capture file. She had to switch the power OFF/ON
to continue. All retrieved mail was obviously lost.
One day, I had a similar
experience. After having written a long and difficult letter, something went
wrong. The outfile was closed without warning. The resulting file size was
0 bytes.
Both problems were solved
by the MS-DOS program CHKDSK run with the /F option. If you ever get this
problem, and have an MS-DOS computer, try CHKDSK or Scandisk. They may save
your day.
Anonymous mail
Some day, you may want to send a message anonymously. Try
Hushmail, a service designed
by hackers for total security. The mail message's headers are gone. Nobody
knows where or who you are.
Internet's Anonymous re-mailers
will also let you do that. For a list of servers and directions, check
http://anon.efga.org/~rlist/rlist.html.
Finally, check out the
alt.privacy.anon-server and
alt.anonymous newsgroups for more on anonymous
email.
Finding a friend's email address
The best method of finding a friend's email address is usually to call your
friend and ask. Many people have several mailboxes. Only by asking will you
find out which mailbox is being used!
So, you don't know the telephone
number? On the Web, try find it by following the links at
http://www.contractjobs.com/tel/.
This site offers links to online telephone, fax, and business directories
around the world.
Sometimes, the information
given you by the recipient is not enough. Maybe the address needs an extension
for mail to be routed through gateways to the destination.
Another typical problem is
that the syntax of the address is wrong. Perhaps you made a mistake, when
you wrote it down (KIDCAFE-TOPICS became KIDSCAFE- TOPICS).
The return address in the
received messages' mailer headers may be wrong. It may use a syntax that
is illegal on your email system, or it may suggest a routing that is unknown
to your system. When trying to send mail to this address, the Mailer-Daemon
complains: "This is a non-existent address."
Again, the first person to
contact for help is your local postmaster. On most Internet hosts this is
simple. If you have a mailbox on the ULRIK computer at the University of
Oslo, send a request for help to postmaster@ulrik.uio.no . If you are on
COLNET in Buenos Aires, send to postmaster@colnetr.edu.ar .
POSTMASTER is also the address
to turn to on BITNET. Users of FidoNet or RelayNet, should write to SYSOP.
It may not be that simple
to locate the postmaster on UUCP. The postmaster ID may exist on some systems,
but often he's just a name or a user code.
There are over 100 other
"whois-servers" in more than 15 countries. The systems whois.nic.ad.jp and
whois.ripe.net cover Japan and Europe. The rest of them provide information
about local users. (A list is available on
ftp://sipb.mit.edu/pub/whois/whois-servers.list.)
Directories of subscribers and services
While many hosts let you search lists of local users, no complete global
directory of available electronic addresses exists.
Several services on the Internet
offer help. My favorite is the
Usenet address database . It is also accessible by email to
mail-server@rtfm.mit.edu. To
query, put the following in the body of your text:
send usenet-addresses/[name searching for]
The "name" should be one or more space-separated words for which you want
to search. Since the search is "fuzzy" (that is, all the words you specify
do not have to match), you should list all words you think might appear in
the address, including first and last name, possible username, and possible
parts of the host name. The case and order of the words you list are ignored.
(Send the command "send usenet-addresses/help" to this address for more
information.) Example:
send usenet-addresses/odd de presno
X.400 systems use an address directory according to ITU-TSS standard X.500
that connect several directories. The developers hoped that routing of X.400
messages may eventually be done automatically without the user needing to
know the identity of the recipient's mailbox computer. However, it never
became a big success.
The Lightweight Directory
Access Protocol (LDAP) has been introduced as an alternative to X.500. Many
hope that it will become the comprehensive Internet wide e-mail address
directories of the future. It is a subset of the Directory Access Protocol
(DAP) used to build X500-based directories.
The information contained
in LDAP databases will include vital data such as name and e-mail address,
and can include supplemental data including address, phone, fax, and even
the person's public key which can be used to encrypt messages the user is
sending them. For more information, see
the LDAP home page.
Supplement by checking the
"How to
find people's E-mail addresses FAQ".
FidoNet
Users of this global network can send and receive mail to/from the Internet.
For example, a FidoNet user may use the following method to send to my Internet
address:
Send the message to user UUCP at 1:105/42. The first line of the TEXT of
the message should contain:
To: presno@eunet.no
Add a blank line after the address before entering the text of your message.
FidoNet addresses are composed by three or four numbers;
zone:net/node
or
zone:net/node.point
The FidoNet address 1:105/42 has three elements. "1:" tells that the recipient
lives in Zone number 1 (North America). 105/42 refers to Node number 42,
which receives mail through Net number 105. This node has an automatic gateway
to the Internet.
Another example: Jan Stozek
is sysop of "Home of PCQ" in Warsaw, Poland. The Node number of his BBS is
10. He receives mail through Net number 480. Poland is a country in Europe,
Zone number 2. The address to his system is: 2:480/10. His user name is Jan
Stozek.
You can send an Internet message
to anyone in FidoNet by using the following template (on one long line):
<firstname>.<lastname>@
p<point>.f<node>.n<net>.z<zone>.fidonet.org
Where <firstname> is the person's first name
<lastname> is the person's last name
To send a message from the Internet to Jan, use this address:
Jan.Stozek@f10.n480.z2.fidonet.org
One final example: Ola Garstad in Oslo has the FidoNet address 2:502/15.
Use the address Ola.Garstad@f15.n502.z2.fidonet.org , when sending mail to
him through the Internet.
An updated list of global
FidoNet nodes can be retrieved from most connected BBS systems. (More in
Appendix 1.)
Junk mail
Junk mail, also called spam, is one of the curses of modern society.
We're talking about email messages that you never asked for, unsolicited
commercial mail. Typically, they contain advertising of some product, service,
business, scheme, Web-site, etc.
Junk mail takes time to retrieve,
browse, and delete, one by one. It distracts. For some, it may grow out of
proportions, and become a major nuisance. Most users must pay to receive
it, to a local phone company or an Internet service provider.
What to do? If you get on
someone's mailing list, you can ask the sender to take you off that list.
This may help a little, but not much. There are too many spammers out there.
Besides, now the unscrupulous sender will know that your address is valid,
and you will undoubtedly received more of the same!
Personally, I delete them,
and keep quiet. My communications costs are low, and it takes too much effort
to get off that list.
Others go a long way to protect
themselves by being wary of giving out their email addresses, and of subscribing
to newsgroups and mailing lists. However, sadly enough, the only 100 percent
effective method is to close your mail account, and open another one. Then
you should safe, but only for a while...
If you're at all active on
the net, your address will be picked up by spammers. It's so easy! Programs
like Email Magnet can scan Web sites, newsgroups, and chat channels to retrieve
any string looking like an email address.
When you buy online or ask
for information about something, your email address usually ends up in a
database. Many online vendors sell their collection of addresses to others
together with information about what browser you are using, the domain you
are calling in from, etc. Yet others consolidate your data with information
from hundreds of other databases, each having some other bits of information
about your use of the net, preferences, buying habits, etc.
List brokers offer megabytes
of lists or CD-ROMs full of addresses to anyone willing to pay. Organizations
and individuals offer to send spam mail to names in their private databases.
For a fee, of course.
Filtering is one way to go.
Most modern email programs have a filtering function that lets you automatically
send spams to Trash. They'll filter out mail from given senders, and if they
find certain strings in the subject title or the body of the text.
Spam stoppers are used to
prevent hostile software to pick up your email address from Usenet newsgroup.
A spam stopper is additional characters that makes your address invalid while
making it possible for real users to find out what your real address looks
like.
Example: One of my addresses
is presno@grida.no. By instructing my news reader to show it as
presno@remove-this-bit-for-my-real-address, the information is made useless
for spam software. Note: You are making it difficult for those you
talk with when doing this. I wouldn't.
You can also buy mail-related
utility programs, like MailJail, a
mail filtering add-on for the Eudora email programs. It's first release came
with 250 rules to help thwart spam mail.
Some users even join initiatives
like the SPAM
Filter, a free register of people who do not want to receive junk mail.
It aims at using their list to filter their addresses against addresses collected
by programs such as Floodgate (which automatically builds mailing lists from
newsgroup ostings).
Others report the incident
to the spammer's Internet service provider (ISP). If you do, make sure to
save the original email message with all headers intact. The email header
is the part of the message that shows where the message originated. While
your email program may not be set to display email headers, most programs
let you do it. Generally, ISPs will not take any action against one of their
accounts without proof of the origination of the spam. They often require
the original spam message to be forwarded to them before they will take any
action, with the email header included.
Finally, Whenever you subscribe
to an email based mailing list, make sure to save the welcome message that
the service returns on your disk. These messages usually contain information
about how to get off the list if the volume should become too high. You may
find it easier to consult these files than by trying to get off by writing
the mailing list administrators.
There's a
FAQ on spam, a
SPAM-L
mailing list, hints on
reading email
headers, and
a
tutorial for those in search for more.
For more information
Start with the
E-Mail Resources,
Reviews and Books page.
The Inter-Network Mail Guide
describes how to send mail between mail systems like AppleLink, BITNET,
CompuServe, Connect-USA, EasyNet, Envoy, FidoNet, GeoNet, Internet, MCI,
MFENET, NasaMail, PeaceNet, Sinet, Span, SprintMail, and others.
The guide is posted monthly
to the Usenet newsgroups comp.mail.misc
and news.newusers.questions. Search
it at
http://alabanza.com/kabacoff/Inter-Links/cgi/inmgq.cgi
. It is also available by anonymous ftp from
ftp://ftp.csd.uwm.edu/pub/internetwork-mail-guide.
The "Frequently Asked Questions:
How to find people's E-mail addresses" document is regularly posted to the
Usenet group news.answers. (Retrieval information
is given under FAQ in Appendix 6.) |