Your outgoing greeting should be equally concise. We all know how voice mail and personal answering devices work, so eliminate the drawn-out apology for being away from your desk or on another call and the assurance that the call is very important to you. A fax is a proper method for delivering business correspondence. However, you should never send a private message to an office via fax. Sending jokes is also a bad idea.
Someone is guaranteed to be offended.
Even though the quality of faxes is vastly improved, there could still be problems associated with originals on colored paper. Photocopy it, and fax the white paper copy. Stay away from whiteout. The result can appear as a blotch on the other end. And it's always a good idea to notify the recipient by phone or voice mail that a fax has been sent Office Email.