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E-mail by itself is a powerful tool, and by now you may be sending e-mail messages all over the place. You might even be on a mailing list or two. But there is a lot more to e-mail than just sending messages. If your host system does not have access to ftp, or it doesn't have access to every ftp site on the Net, you can have programs and files sent right to your mailbox. And using some simple techniques, you can use e-mail to send data files such as spreadsheets, or even whole programs, to friends and colleagues around the world.
A key to both is a set of programs known as encoders and decoders. For all its basic power, Net e-mail has a big problem: it can't handle graphics characters or the control codes found in even the simplest of computer programs. Encoders however, can translate these into forms usable in e-mail, while decoders turn them back into a form that you can actually use. If you are using a Unix-based host system, chances are it already has an encoder and decoder online that you can use. These programs will also let you use programs posted in several Usenet newsgroups, such as comp.binaries.ibm.pc.
To help people without ftp access, a number of ftp sites have set up mail servers (also known as archive servers) that allow you to get files via e-mail. You send a request to one of these machines and they send back the file you want. As with ftp, you'll be able to find everything from historical documents to software (but please note that if you do have access to ftp, that method is always quicker and ties up fewer resources than using e-mail).
Some interesting or useful mail servers include:
Most mail servers work pretty much the same -- you send an e-mail message that tells them what file you want and how you want it sent to you. The most important command is "send," which tells the computer you want it to send you a particular file.
First, though, you'll need to know where the mail server stores that file, because you have to tell it which directory or sub-directory it's in. There are a couple of ways to do this. You can send an e-mail message to the archive-server that consists of one line:
index
The server will then send you a directory listing of its main, or root directory. You'll then have to send a second message to the archive server with one line:
index directory/subdirectory
where that is the directory or directory path for which you want a listing. An alternative is to send an e-mail message to our old friend archie, which should send you back the file's exact location on the archive-server (along with similar listings for all the other sites that may have the file, however)
Once you have the file name and its directory path, compose a message to the archive server like this:
send directory/subdirectory/file
Send off the message and, anywhere from a few minutes to a couple of days later, you'll find a new message in your mailbox: a copy of the file you requested. The exact time it will take a file to get to you depends on a variety of factors, including how many requests are in line before yours (mail servers can only process so many requests at a time) and the state of the connections between the server and you.
Seems simple enough. It gets a little more complicated when you request a program rather than a document. Programs or other files that contain unusual characters or lines longer than 130 characters (graphics files, for example) require special processing by both the mail server to ensure they are transmitted via e-mail. Then you'll have to run them through at least one converter program to put them in a form you can actually use. To ensure that a program or other "non-mailable" file actually gets to you, include another line in your e-mail message to the server:
encoder
This converts the file into an encoded form. To decode it, you'll first have to transfer the file message into a file in your home directory. If you are using the simple mail program, go into mail and type
w # file.name
where # is the number of the message you want to transfer and
file.name is what you want to call the resulting file. In pine, call
up the message and hit your `O' key and then `E'.
You'll then be asked
for a file name. In elm, call up the message and hit your `S' key.
You'll get something that looks like this:
=file.request
Type a new file name and hit enter (if you hit enter without typing a file name, the message will be saved to another mail folder, not your home directory). Exit mail to return to your host system's command line. Because the file has been encoded for mail delivery, you now have to run a decoder. At the command line, type
uudecode file.name
where `file.name' is the file you created while in mail. Uudecode will create a new, uncompressed file. In some cases, you may have to run it through some other programs (for example, if it is in "tar" form), but generally it should now be ready for you to download to your own computer.
One further complication comes when you request a particularly long file. Many Net sites can only handle so much mail at a time. To make sure you get the entire file, tell the mail server to break it up into smaller pieces, with another line in your e-mail request like this:
size 100000
This gives the mail server the maximum size, in bytes, of each file segment. This particular size is good for UUCP sites. Internet and Bitnet sites can generally go up to 300000. When you get all of these files in mail, transfer them to your home directory. Exit mail and call up each file in your host system's text processor and delete each one's entire header and footer (or "signature" at the end). When done with this, at your host system's command line, type
cat file1 file2 >bigfile
where file1 is the first file, file2 the second file, and so on. The > tells your host system to combine them into a new megafile called bigfile (or whatever you want to call it). You can then run uudecode, tar, etc. One word of caution, though: if the file you want is long enough that it has to be broken into pieces, think of how much time it's going to take you to download the whole thing -- especially if you're using a 2400-baud modem!
There are a number of other mail servers. To get a list, send an
e-mail message to:
send usenet/comp.sources.wanted/How_to_find_sources_(READ_THIS_BEFORE_POSTING)
You'll have to spell it exactly as listed above. Some mail servers use different software, which will require slightly different commands than the ones listed here. In general, if you send a message to a mail server that says only
help
you should get back a file detailing all of its commands.
But what if the file you want is not on one of these mail servers? That's where ftpmail comes in. Run by Digital Equipment Corp. in California, this service can connect to almost any ftp site in the world, get the file you want and then mail it to you. Using it is fairly simple -- you send an e-mail message to ftpmail that includes a series of commands telling the system where to find the file you want and how to format it to mail to you.
Compose an e-mail message to
ftpmail@decwrl.dec.com
Leave the "subject:" line blank. Inside the message, there are several commands you can give. The first line should be
reply address
where "address" is your e-mail address. The next line should be
connect host
where "host" is the system that has the file you want (for example: wuarchive.wustl.edu). Other commands you should consider using are "binary" (required for program files); "compress" (reduces the file size for quicker transmission) and "uuencode" (which encodes the file so you can do something with it when it arrives). The last line of your message should be the word "quit".
Let's say you want a copy of the U.S. constitution. Using archie,
you've found a file called, surprise!, `constitution', at the ftp site
archive.cis.ohio-state.edu, in the `/pub/firearms/politics/ rkba'
directory. You'd send a message to
reply adamg@world.std.com connect archive.cis.ohio-state.edu binary compress uuencode get pub/firearms/politics/rkba/constitution quit
When you get the file in your mailbox, use the above procedure for copying it to a file. Run it through uudecode. Then type
uncompress file.name
to make it usable.
Since this was a text file, you could have changed the "binary" to "ascii" and then eliminated the "uuencode" file. For programs, though, you'll want to keep these lines.
The uuencode and uudecode programs will also come in handy if you ever want to send your own files to somebody else.
If both you and your intended recipient communicate via Unix-based host systems, then it's pretty easy, because almost all Unix host systems will have encoder/decoder programs online.
First, upload the file you want to send to your friend to your host site. Ask your system administrator how to upload a file to your name or "home" directory. Then type
uuencode file file >file.uu
and hit enter. "File" is the name of the file you want to prepare for mailing, and yes, you have to type the name twice! The > is a Unix command that tells the system to call the "encoded" file "file.uu" (you could actually call it anything you want).
Now to get it into a mail message. The quick and dirty way is to type
mail friend
where "friend" is your friend's address. At the subject line, tell her the name of the enclosed file. When you get the blank line, type
~r file.uu
or whatever you called the file, and hit enter. (on some systems, the `~' may not work; if so, ask your system administrator what to use). This inserts the file into your mail message. Hit control-D, and your file is on its way!
On the other end, when your friend goes into his mailbox, she should transfer it to her home directory. Then your friend should type
uudecode file.name
and hit enter. This creates a new file in her name directory with whatever name you originally gave it. She can then download it to her own computer. Before she can actually use it, though, she'll have to open it up with a text processor and delete the mail header that has been "stamped" on it. If you use a mailer program that automatically appends a "signature," tell her about that so she can delete that as well.
But what if your friend only connects with a non-Unix system, such as CompuServe or MCIMail? There are programs available for MS-DOS, Apple and Amiga computers that will encode and decode files. Of course, since you can't send one of these programs to them via e-mail (how would they un-encode it?), you'll have to mail or give them a diskette with the program on it first. Then, they can get their message, run it through a text editor to delete the header, and finally decode the file. If they want to send you files in return, they'll also want an encoder
For MS-DOS machines, you'll want to get uunecode.com and uudecode.com. Both can be found through anonymous ftp at wuarchive.wustl.edu in the `/mirrors/msdos/starter' directory. The MS-DOS version is as easy to use as the Unix one: Just type
uudecode filename.ext
and hit enter.
Mac users should get a program called uutool, which can be found in the `info-mac/util' directory on sumex-aim.stanford.edu.
Once again, be careful with large files. Although large sites connected directly to the Internet can probably handle mega-files, many smaller systems cannot. Some commercial systems, such as CompuServe and MCIMail limit the size of mail messages their users can receive. Fidonet doesn't even allow encoded messages. In general, a file size of 30,000 or so bytes is a safe upper limit for non-Internet systems.
One other thing you can do through e-mail is consult with the Usenet Oracle. You can ask the Oracle anything at all and get back an answer (whether you like the answer is another question).
First, you'll want to get instructions on how to address the Oracle (he, or she, or it, is very particular about such things and likes being addressed in august, solemn and particularly sycophantic tones). Start an e-mail message to
oracle@iuvax.cs.indiana.edu
In the "subject:" line, type
help
and hit enter. You don't actually have to say anything in the message itself -- at least not yet. Hit control-D to send off your request for help. Within a few hours, the Oracle will mail you back detailed instructions. It's a fairly long file, so before you start reading it, turn on your communications software's logging function, to save it to your computer (or save the message to a file on your host system's home directory and then download the file). After you've digested it, you can compose your question to the Oracle. Mail it to the above address, only this time with a subject line that describes your question. Expect an answer within a couple of days. And don't be surprised if you also find a question in your mailbox -- the Oracle extracts payment by making seekers of knowledge answer questions as well!
"If just one piece of mail gets lost, well, they'll just think they forgot to send it. But if *two* pieces of mail get lost, hell, they'll just think the other guy hasn't gotten around to answering his mail. And if *fifty* pieces of mail get lost, can you imagine it, if *fifty* pieces of mail get lost, why they'll think someone *else* is broken! And if 1GB of mail gets lost, they'll just *know* that Arpa is down and think it's a conspiracy to keep them from their God given right to receive Net Mail ..." --- Leith `Casey' Leedom
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