Things to keep in mind when Sending or Receiving E-Mail Attachments:

• 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.
• Make sure you know what operating system the recipient has ie. Mac or Windows etc.
• Make sure that the recipients e-mail program can handle the encoding on
  your attachment ie: is it MIME or BINHEX encoding. Internet e-mail 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 and, 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 e-mail packages. There are three popular encoding schemes for e-mail attachments: MIME (multipurpose Internet mail extensions), BinHex, and uuencode--and different e-mail 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.

Even if you've checked everything forward and backward, things can still go wrong with e-mail. 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 e-mail. Most online systems don't immediately send or receive e-mail from the Internet--often, they handle such messages only every hour or so. If the message was sent directly over the Net, check with Simply Internet. 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 e-mail 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 e-mail, 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 e-mail 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 e-mail 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 e-mail 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 e-mail 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 e-mail 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.

E-Mail Help Resources on the web: