I used Gandi for exactly this purpose years ago. Then emails from certain popular domains suddenly stopped getting through to me. When I complained, they told me in somewhat vague language to use a proper email service instead of a free add-on to a cheap domain plan.
Did you have difficulty receiving or sending mail? I haven't noticed such problems with my Gandi inboxes, but I know the big email providers like Google and MS do a lot of gatekeeping. If the host in France is the problem, you can use your domain at another host such as Proton.me which I do for my main account.
Yes, receiving. I just got the impression that email wasn't really something Gandi actually wanted to do rather than a box they needed to tick. And I think that may well be the case with a lot of domain registrars and their basic plans.
