I also use Encyro, as @Just-Lisa-Now- said very affordable, I've used it for two years now, and love its simplicity 

I assume the client still needs to go through the authentication process where they are asked random questions?  Is it similar to the esignature platform that ProSeries offers?

I have never used Intuits esignature, but Encyro uses  authentication by sending text code to clients cell phone to log in

Have absolutely no intention of using that....

I used 3 of 5 freebies ProSeries allowed.  I wouldn't pay for the service.  Didn't feel it saved ME any time but the client liked that they didn't have to take time to stop by office to sign.

BUT, for 8879s IRS requires Knowledge Based Authentication (KBA). That's what the big charges are for.

Sounds like Lisa's and Terry's products don't meet that standard. Should be fine for all kinds of other stuff, though.

Encyro says it uses KBA for IRS 8879s.

 https://www.encyro.com/esign#kba

Great.

I haven't used this and do not plan to in the future. I enclose the bill, form 8879 with a self addressed envelope to all my clients.  

At that price, and satisfying KBA requirements, I will check it out.

@JRC Do you also mail the return for them to review before signing ?

YES!

For my mail in clients, I do the same as JRC.   Send off the whole package with instructions to review, sign the 8879s and return to me....I find it odd that many of them sign the 8879, but keep it, rather than send it back to me!    So for these slow readers (LOL) encyro will give me another option for sending and receiving the signatures when they forget to send them back and a more secure way to send a PDF copy for those that request them, rather than password protecting an email attachment.

Now I just have to retrain myself to use this other method...old dogs, new tricks and all  😄

Genuine question here:  is anyone aware of the IRS ever auditing a tax practice to determine if the KBA process was actually used for e-signatures on Form 8879?  Or, for that matter, the IRS auditing a tax practice to confirm actual possession of a Form 8879 signed by the client?

Years ago (20?) IRS asked me to produce some signed 8879s. About 3 or 4 a year for about 3 years. Nothing since then.

I was asked for less than a half dozen about 8 years ago. I submitted them and never heard anything back. I use the tried and true mail with the return method. For many clients, the Digital KBA approach is a non-starter and is not efficient for my practice. 

For the lay person here, is DocuSign or Adobe sufficient for IRS requirements?

Per IRS requirements, the answer is no, it is not sufficient.