Error in Dynamically setting the Recipient (To) Email Address in Contact Form 7

Hi,

I an trying to set dynamic recipient for a form as described in the following link:
https://sevenspark.com/wordpress-plugins/how-to-dynamically-set-the-recipient-to-email-address-in-contact-form-7

But, I’m getting configuration error(Invalid mailbox syntax is used).
https://ibb.co/zQvgbND

Kindly let me know how to fix this issue.

Thanks in advance.