Which could be legally challenged. If a club has sent it on time, you can't say the transfer doesn't count because the receiving machine was out of paper (or busy etc).
The part of the FA (or whichever branch it was) that go through all the transfers (all leagues) don't use fax machines. They visited part of their office on SSN on deadline day.
What if a few clubs submit there's just before the deadline, and the machine is printing stuff off?