Newsletter subscription & admin email

Hi, I've been using this plugin for several months. And it's good.
I read that next year a user here ask if we could customize the mail with object: "Newsletter subscription" (that the admin receives)

This:
Subscriber details:
email:
first name:
last name:
gender:
...
token:
status: C

The developer said that we could not modify this email.
This happened one year ago.

Now I think it's very important to modify this mail... because of the GDPR.
I'd like insert the privacy acceptance.
How can I have the provided consent in my mail?

It's very important to have the proof.

thanks
alexia