You'll have to fully investigate and see if that service procedure is secure. I don't know if they have a secure method of uploading files and sending you the results. You should question them. Their site says it's delivered by email. Well, regular email is not a secure method for sensitive files. So unless they can explain how they secure a sensitive tax document for an email delivery, I'd be concerned about that.
It would also be good to know how well they secure the info once they receive it and store it on their servers. Their phone number is listed in their FAQs. You may wish to talk to them to explain all their security mechanisms, but in the end you may be at their mercy.
I am seeking information from anyone who has used this service.
Since Turbotax does not offer any way to print old *.tax files it would be nice if they could recommend someone who does. Judging by he number of inquiries on the subject it is a service with a demand.
I'm afraid that we can't officially vouch for any third party service. You will have to check them out on your own.
I was desperate so I gave them a try. They turned it around in less than 24 hours. I can say whether they sold my info on the dark web or not, but they did get me a copy of my return in PDF format from that crazy TurboTax version that I couldn't open. I will post a new reply if my identity is stolen in the next few months. 🙂