can my recommender sign the letter using e-signature?

Does anyone know? I've one professor who said he will only do e-sign...

to Mason:

I'm not sure but if I were you I'd definitely get handwritten signatures for everything. E-signs are so easy to fake....

And gosh that's a tough person you're dealing with. I've seen people who were super confused with scanning/digital stuff but only e-sign? It really isn't hard to print and sign.....