E-mail file attachments - The PC Corner - Column

Business Economics, Oct, 1998 by John H. Qualls

Internet e-mail is only capable of transmitting a seven-bit character. I don't know why this is, but it certainly complicates the life of anyone who wants to send a binary file through the Internet e-mail system. In his guest column several years ago, Mike Anderson described this problem in some detail. The only way to get around this problem is to encode the binary file before sending it, so that the resulting file contains only the 128 characters that form the basic ASCII character set.

Somehow, in the intervening years, I thought that this problem had been taken care of. Occasionally, I would get an e-mail that would have the message text followed by lines and lines of weird-looking garbage, with something about "UU encoded" or "MIME" at the beginning of the garbage. Most of the time, though, I would get a nice clean e-mail, along with a notice that there was an attachment that had been neatly stored in some subdirectory on my computer. I figured that the problem of sending eight-bit binary files had been solved by the nice people who ran the Internet, and our attached files were magically transported to their intended destination, somehow piggy-backed on the text of our e-mails.

Gentle readers, I am here to tell you that such is not the case. The nice folks who run the Internet have not gotten any smarter. Rather, our thanks should go to the nice folks who came up with the various e-mail packages that do a better job of simplifying the process. All of the more popular e-mail packages (e.g., Microsoft Exchange and Outlook, the various web browsers, the proprietary services like CompuServe and AOL, etc.) are now quite good at taking an incoming e-mail and separating the text portion of the message from the encoded binary file, then placing the e-mail text in your "In" basket and the decoded binary file in some other subdirectory under its original name. Similarly, these e-mail packages also encode any binary file that you attach to your outgoing e-mail and stick the encoded text right after your e-mail message before committing it to the bowels of the Internet.

What you occasionally see as a lot of garbage at the end of an e-mail is actually an attachment that your e-mail program was unable to recognize and properly decode. Don't blame your e-mail program for this. The odds are just as good that whoever sent you the attached file had an e-mail program that messed up the encoding task at their end.

So, where does that leave you when you get an e-mail with an important attachment that didn't come through, except as a lot of gobbledygook? Or, worse yet, what do you do if you (like I) have to use a TELNET-based e-mail system that does not support attached files?

Not to worry, folks. There are a score of freeware/shareware programs available on the Web that do a pretty good job of encoding and decoding these pesky binary file attachments. Ed Mennis, the editor of Business Economics, has found it necessary to get one of these programs to overcome a real problem with file attachments sent via several e-mail systems that shall remain nameless.

The program that I use is called "XFerPro," otherwise known as Information Transfer Professional. It is a shareware package that does a good job of encoding and decoding binary files into/from the four most popular formats used on the Internet. The two formats that I have the best luck with are UU encoding/decoding and MIME (Multipurpose Internet Mail Extensions). UU encoding/decoding has been around the longest, but it unfortunately does not do a good job of passing data between ASCII-based computers (e.g., PCs) and EBCDIC-based machines (e.g., IBM mainframes). The newer MIME standard solves this problem. Personally, I have had more luck using UU rather than MIME and will be using it to send this column to Ed, insh-allah.

For more details about Information Transfer Professional, contact Sabasoft, Inc. Their web site is "www.sabasoft.com" and their e-mail address is "sabasoft@aol.com."

John H. Qualls is Senior Economist, National Center for Economic and Financial Information, Ministry of Finance, Riyadh, Kingdom of Saudi Arabia. His e-mail address is jhqualls@delphi.com