User habits contribute a great deal to how quickly mailboxes fill up. Always help users develop good habits to work smarter and make better use of system resources. Three habits are particularly important:

  1. Don't include graphics in your AutoSignature file. I have never understand why people insist on including company logos in their AutoSignature files. Logos add as much as 300KB to every message. People don't realize that, first, internal recipients don't need to receive their own company logo and, second, gateways invariably strip graphic elements out of AutoSignatures, so most people outside the company won't see the logo anyway.
  2. Include only necessary text in your replies. In Outlook, you can easily include all the original message text in the reply to everyone who received the original. The result is inbox folders stuffed with the original message and all its replies—a lot of redundant information.
  3. Don't send a large document to a distribution list unless that method is the only way people can receive the information. In Windows, people can easily drag a large document into a message and send it off to the world. A 3MB PowerPoint presentation—even slides that display useful data graphically—is a real pain for anyone whose quota is at the limit or who works remotely over a dial-in telephone link. Better etiquette is to send a reference to a document on a Web site, in a public folder, or on a networked file share.