I have a loan (still within SOL) that was sold to another company for collection a few months ago. That company has sent me verification of the debt in the form of the loan agreement and my payment history.
The loan was initiated online, so there is no physical signature. The bottom of the loan agreement provided to me says that I acknowledged receipt of the agreement by checking the submit button and state that I have read and agree to the terms and conditions. It further says I acknowledge and agree that any digital or electronic signature represents my signature on the agreement.