This email from Engie is indeed real and it is best to respond to it.

In an age of scams everywhere, fake calls, fraudulent text messages, and even (almost) perfect emails from criminals, vigilance is essential when receiving a message. Whether on your cell phone or in your inbox, you need to be extra careful when opening content and, especially, clicking on a link. This sometimes leads to extreme caution... at the risk of missing out on genuine communication.
This is particularly the case with an email that Engie sends to some of its customers. "We recently tried to send you a document by mail and it arrived as undelivered," it says. The customer is asked to click on the "I'm checking my address" link to ensure that the information provided is correct. While some emails of this type are often fraudulent, this is a genuine message from the energy company.
Yet, some— Linternaute first and foremost—initially thought it was a scam. The origin? The sender address: " [email protected] ." This wasn't mentioned in the official list compiled by the company in its prevention information sheet, posted on its website. Thus, the more cautious deleted the email. The problem: the group's complaint was genuine, and it was worth looking into.
The company simply hadn't updated the authentic shipping addresses. This has now been corrected. For those who haven't opened or deleted the email, you should log into your personal space on the Engie website and provide your correct postal address so that the company's mailings can reach you.
L'Internaute