I realize that fax machines are less and less common, but when I recently had the occasion to still use one, I was reminded of one of their inherent design flaws...the dial 9 first problem. Every time I have been around a fax machine in a corporate setting, someone has always asked the poor person sitting next to the fax machine whether you need to dial 9 before sending.
Fax machines should be either initially set up to know whether or not they need to dial 9 when they call. Then let the machine handle things. If someone unfamiliar with the system dials 9 first, ignore it.