No Attachment is the Best Attachment!
Attachments take time to download. The bigger the attachment, the longer it takes to download. If you mail a big attachment to many people, bandwidth could be clogged or wasted. They would also take up disk space on the recipient's computer.
Some E-Mail attachments may not be necessary. Consider faxing lengthy documents that might otherwise be E-Mailed. Or, if time is not really an issue, use regular mail services, UPS or Federal Express.