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Sending file attachments is one of the most useful things you can
do with email. What is an email attachment? It's a computer file that you
send -- across the Internet -- attached to an email message!
Things to keep in mind when Sending or Receiving Email Attachments:
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Make sure that the recipient of you attachment has a program that can read
the file you are sending ie: if you are sending an Excel file, they
must also have Excel.
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Make sure you know what operating system the recipient has ie. Mac
or Windows etc.
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Make sure that the recipients email program can handle the encoding on
your attachment ie: is it MIME or BINHEX encoding.
Internet email and Usenet news posts were designed for plain text messages.
As such, many systems expect the messages to only contain printable characters
from the 7-bit ASCII character set. That poses a problem for sending files,
such as images, sound, video, spreadsheets and programs which can contain
any combination of 8-bit binary data. This even poses a problem for formatted
documents, since many word processors embed binary control fields in the
files.
The way around this limitation is to encode the binary data (attachment)
into ASCII characters before sending. To the mail and news systems that
the messages travels through, the file is just so much text. At the receiving
end, the message is decoded back into the original file, none-the-worse
for the experience. Many mail and news programs automate the encoding and
decoding. However, sometimes a separate program may be required.
It sounds easy, but a lot of potential pitfalls can ultimately befall
attachments. First, you need to make sure the file you're sending is in
a format that can be read by the person on the receiving end. For example,
if you are sending an Excel spreadsheet, you need to make sure that the
recipient also has a program that can read Excel. As well, you need to
find out what kind of operating system your recipient has. If it's a large
file you're sending, you may need to compress it--which again brings up
the issue of format. Another variable is the encoding standards used by
different email packages. There are three popular encoding schemes for
email attachments: MIME (multipurpose Internet mail extensions), BinHex,
and uuencode--and different email packages often use different types of
encoding. Finally, not all online services can handle attachments, so it's
important to know your service's limits before you try to send a file.
For more info on obtaining encoding and decoding utilities please
go to the Useful Windows Programs page.
Even if you've checked everything forward and backward, things can still
go wrong with email. Your attachments can get munched or dropped, messages
you're sure were properly addressed may be sent back, and mail may arrive
hours or even days late. With that in mind, here are a few options to consider
when things don't work out as planned.
If the message either originated from or was received by a commercial
online service, the delay may be due to the way the service handles email.
Most online systems don't immediately send or receive email from the Internet--often,
they handle such messages only every hour or so. If the message was sent
directly over the Net, check with your Internet Service Provider. Mail-handling
systems sometimes hang, thereby delaying mail.
Troubleshooting Attachment Problems
If you receive an attachment and it looks like a bunch of gobbledy-gook,
don't despair, there is still hope.
The first step is to figure out what kind of encoding has taken place.
The email application or the attached document itself should say whether
it's in BinHex (these files sometimes have the extension .hqx) or uuencoded
(.uu) format.
When you see a file with the BinHex extension, just drag and drop it
onto StuffIt Expander for the Mac or StuffIt Expander for Windows; this
translates the file back into the original binary format. If you're on
a Mac, you can also use an application called BinHex 4.0. Once you're in
the program, just open the file using the Upload-Application command to
translate it back into binary format. Select Application-Upload to do the
opposite. On Windows systems, you can use a program called MacSee, which
translates BinHex files back into binary format.
StuffIt Expander for the Mac also handles uuencoding; on Windows machines,
WinCode does the same. In some cases, the attachment may be dumped into
the body of the message itself, and may even be split into multiple documents.
(Older versions of America Online had a nasty habit of doing this.) Even
these fractured files can sometimes be salvaged. Look for two lines like
this:
-------------------------------start 994-------------------------------
-------------------------------end-------------------------------------
The "start" line will probably appear on the first email, and the "end"
line will be in the last message. One by one, take each message in order
and cut and paste the ASCII code into a new document. (Make sure you paste
the messages in the order they were received, or your efforts will be doomed.)
When you finally have a complete document, save it and then use one of
the above applications to translate it back into binary form.
If you can't read the file using one of the applications listed above,
you may need to ask its originator to resend it. This time be sure to agree
on an encoding standard, and ask the sender to check the setting in his
or her email application. When going the other way, you can avoid putting
recipients through this by making sure everything is set up properly on
your end. Set your email program to encode attachments using the MIME standard
rather than BinHex or uuencode. Also, if you have any doubts about the
type of compression used by your email application, turn compression off.
(Emailer, for example, defaults to StuffIt as a compression standard, making
for documents that are problematic for most Windows users and all Unix
users.) You can access these settings in the Preferences or Settings menu
of your email program.
If you're sending a document that's basically text and you're unsure
how it will travel, translate it into raw text and paste it into the body
of the email message. Granted, it will lose all that nice formatting, but
you can be sure it will arrive at its destination intact. For larger files,
or those that include audio, video, or graphics, your only last-ditch option
may be to copy the file onto a disk and send it via the old-fashioned postal
service.
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