I've worked at a variety of companies, some of which have officially stated that e-mail is the preferred method of communication. I have never, however, worked at a company which ever bothered to tell employees why they should try to avoid mailing around MS Word attachments. The article really applies to any sort of attachments--even those from OpenOffice, or MS Works, or any other program.

Why should you avoid mailing around MS Word attachments?

Well, there are technical and non-technical reasons for avoiding MS Word attachments. Believe it or not, there are also good reasons for sending around Word docs. But those are far less common than you'd think, and can often be completely avoided by using some collaborative tools.

Reasons to avoid attachments

• File Size: Every file MS Word creates is quite large. Just for fun, I fired up MS Word 2003, and created a text file with two words in it: "Hi There". Then I saved it, and checked the file size. 20 KB, or 20480 bytes. Believe it or not, that message can be stored in 8 bytes. If you like math, you may see that a word document for a two-word message is some 2500 times as big as it needs to be. That's just plain inefficient. You may not think that email size is a big deal, because you've got a cable modem. But I know of users who have a hard time getting 19 kilobit connection speeds--for them, the difference in load time is enormous. The small message takes a few seconds, the big message takes over ten seconds.
• Launch Speed: MS Word takes time to load--time to load on your machine, and time to load on the reader's machine. If you're just sending a short message, why waste that time? I'm not sure about you, but my time is fairly valuable to be. Time spent looking at an hourglass while some word processor loads is not time that I consider well-spent. I worked at a company that had a cafeteria. They send the menu out as a word attachment. Did I read it? No. It was a pain to open, so I just called the phone number where I could listen to the menu. Asking me to open a word doc so I can read your menu is like asking me to put on a shirt and tie to go to the bathroom--it's overkill, and it's too much to ask. (thanks for the quote, Jose!)
• Virus Scanning: MS Word documents can actually contain viruses! And some companies have virus filters that simply throw away all attached Word documents. Sending your message in an attached document may mean that the recipient never receives it. Why send a message in a form that can carry the risk of infection?
• Search Functions: Most email programs today allow you to search through your old emails. Guess what? They can't look inside Word documents--so if you're looking for critical information, your email program won't be able to find it.
• In-line replies: One of the great strengths of most modern email programs is the ability to reply to someone's message in the middle of their message. That is, their text is show in red or blue (or prefixed with one or more > symbols), and your message is in a different color. This allows for a very conversational flow to email. Note that certain mail programs (such as MS Outlook and Outlook Exchange) prefer to have people put all their reply at the beginning--despite the fact that everyone else has been doing it differently for a long time.
• Recipient must have MS Word: Do you really want to make someone go out and pay a few hundred dollars just so they can easily read your messages? Some users will just throw your messages away, rather than fork out the cash. If they absolutely have to read your messages, they'll pony up the money, though.
• Very Editable: MS Word doesn't have controls to prevent people changing what you sent. Normal email doesn't either, mind you. But if you don't want people making changes to what you send, you shouldn't be sending Word documents around.
• Different Versions: What looks cool in your version of MS Word might not look good in the next, or previous version of word. It might look funny for someone running MS Word on Mac. If the recipient uses Linux, they can't even _get_ MS Office--so you'd better hope it looks good in OpenOffice. And if they're using webmail, or a coffee-shop computer, it's probable they won't be able to read your message at all.

Good and bad reasons people send attachments

• Everyone has word: Wrong. My employer pays $250-$300 per machine to get MS Office. Adobe reader (for viewing PDFs) is free. Almost no machines sold in Best Buy or CompUSA include MS Office. Microsoft has finally started shipping a copy of Office for $200 with new machines, but it's only good if you buy it at the same time as your new machine, and many manufacturers don't include it. Most people who are using Word at home are probably using pirated copies--and do you really want to encourage illegal behavior?
• It's easier and I already know MS Word: Really? Which list is shorter?
  1. Open MS Word
  2. Type up message into file
  3. Save file
  4. Open up Email program
  5. Create email
  6. Address email
  7. Attach document
  8. send email
  
  
  1. Open up Email program
  2. Create email
  3. Address email
  4. Type message in email
  5. send email
  
  One of those lists seems three steps shorter to me...
• My email program doesn't have a spellchecker: Really? Thunderbird and Eudora have one built-in. So does Outlook Express and MS Outlook. Netscape Navigator has had one for a long time. Seriously, virtually all email programs have a spellchecker. Even my command-line program (mutt) does.
• When I want to send a message, I automatically open MS Word: Well, that seems compelling, except for the fact that humans can learn better ways to do things. When you were very young, and you needed to go to the bathroom, you just went--after all, you were wearing a diaper. Later, you learned that it was more convenient (and faster) to relieve yourself in a bathroom. You learned a better way to do things. Typing up your messages directly in the body of an email is a better way to do things--it's faster, it requires less software (and expense) on both ends, and it actually is simpler.
• Formal Document: If you're sending a formal document that may need to be archived indefinitely, or printed for review, an attached document is a good choice. But if you're sending a legal contract, or a status report, do you want to send it in a format that someone can modify without any effort at all? Adobe's Portable Document Format (commonly called PDF) is a much, much better choice for Formal Documents. It can be easily read, printed, but not changed. How do you make PDFs? You either buy Adobe Acrobat from adobe.com, or you use OpenOffice.org's free office suite, which can not only read and write MS Word documents, but can also save them in PDF format.
• Formatting lost in email:: If you're just playing with colors and different fonts, most email programs these days can use HTML email, which is ugly for people who can't read it, but is much more efficient than an attached document. If you're doing fancy stuff with line breaks at specific points, and indentations, you should be looking at PDF. Why? Only PDF guarantees that your document will look exactly the same on the client computer as on yours. MS Word does--MOSTLY--but if you're sending a legal document, is 'mostly' good enough for you? PDF documents also include all necessary information (such as fancy fonts) for displaying your document properly. MS Word doesn't do that.
• Seriously, this data doesn't format right in email: No one expects you to type up spreadsheet data into an email. By all means, attach spreadsheet documents as you wish.
• Collaborative Design Document: Well, this looks like a good choice for MS Word, but you're probably better off installing a Wiki--which is a special collaborative web-based system, where any authorized user can make changes, and changes are tracked through a database. I've used Word's 'show revisions' feature, and it's ugly. In my experience, it is far inferior to the searchable-changes features available with virtually any wiki. What does a wiki cost? It's free, all you need is a webserver to put it on.
• Sending a template: Finally, a GOOD reason to send an MS Word document. If your company has standardized on templates for various tasks, then sending someone a template is a good thing.
• The recipient is just going to print it anyway: Yeah, I know guys like this too. If this is the case, consider printing it out and putting it in their inbox, by their desk. Or snail-mailing it, or faxing it.
• I want to save a copy of what I sent: I do too! Every email program I've seen has an option for saving a copy of all sent items. I know that Mozilla Thunderbird and Eudora both do, as do MS Outlook and Outlook Express.

Why not send all email as a PDF?

Did you read the reasons above? If your data doesn't have to be in a specific format, and it doesn't need to be archived by someone, the whole comment about "shirt-and-tie for bathroom" still applies to PDFs.

Summary

Sending MS Word document attachments is inefficient and highly over-utilized. If you're sending a message that fits better on a sticky-note, just send it in email. If you're sending something official that you don't want the recipient to modify, send it as a PDF.