A fax has legal protections no other electronic communications has. It needs to change, but won't. There is a reason why faxes are still used.
It looks like a fax seldom has much more legal protection than other electronic communications. See for example: http://www.adamsdrafting.com/f...
A scanned seignature would generally still stand up as binding. It looks like an "e-signature" is actually MORE binding than a faxed one:
"Fax signatures are probably the primary way contracts are signed today, and broadly speaking, basic contract law recognizes a large variety of signature types where a mark or sign is made with an intent to subscribe to the terms of an agreement. Thus the question posed is the right one—not are fax signatures and pdf signature pages valid to indicate assent to the term of a contract—they generally are—but are they enforceable. More specifically, the question is whether they satisfy the Statute of Frauds, which provides that in order to be enforceable, certain types of agreements must be evidenced by a writing signed by the party to be charged.
Over the years, courts have concluded that telegrams, telexes, telecopies, facsimiles, and e-mails are writings satisfying the Statute of Frauds. But to eliminate any uncertainty, a majority of states have gone further and explicitly adopted legislation allowing the introduction of fax signatures into evidence for disputes involving routine business transactions. However, not all have taken this extra step. The federal government and the UETA have actually gone further in the case of electronic signatures, deeming most electronic signatures meeting their provisions equivalent to written signatures."