Is it safe to sign tax forms over email?

Episode 1373 (10:21)

Larry from Petaluma, CA

Larry has been asked to submit his tax returns electronically, which has a clickable link to electronically sign. He's hesitant, especially since a similar attempt was a phishing scam a few years back. Leo says that Right Signature, Docu Sign, and others give you a secure link to digitally sign. The problem is, how do they verify it's him that clicks on the link and digitally signs? They should be requiring a PIN code, or second factor authentication.