Changing the default DNS Name server in Gandi should be a trivial task. However, if you follow the official guide from Netlify, you will lose Gandi's Email service(since nameserver now pointing to Netlify, you are not able to maintain a customized DNS record).
I'll provide you a step-by-step guide of how to correctly point your DNS record from Gandi to Netlify, so that people can reach your Netlify website through your domain name. In the meanwhile, keep the Gandi Email service working, you can use your sweet email address: you@yourdomain.com
provided by Gandi for free.
This blog was inspired by this Netlify Community post.
Now, let's get started!
#dns-settings
section, remember your app URL (fig. 2)
1@ 1800 IN ALIAS your_netlify_app.netlify.app.2www 10800 IN CNAMES your_netlify_app.netlify.app.
Forget about what Netlify guide indicates, you can safely ignore the DNS Nameservers setup and leave it as default(fig. 4)
Now you can go set up your email account and try out the POP3/IMAP Account(For incoming email) and SMTP Account(For sending email) provided by Gandi.
I hope this simple guide helps you setup your DNS redirection, and please feel free to connect me on Twitter :)