Mail Tag has syntax errors

Hello

I created a form using contact from 7. I want to send emails to front end users to say them thanks to request something. I am unable to send mail 2 to front end user. Please tell me if there is any other way to send user automatic reply on successful submission.

Also, in both email template forms (mail and mail2), I am unable to add mail tags in “To” and “From”.
It generates the error: “This field has syntax errors. How to correct this?”. When I go to this link I found that I can put tags in these fields but I am unable to do this.

I am putting the “[email-414]” in mail 2 To section. “[email-414]” is my email field in form. Which was replaced with “[your-email]”.

Thanks