Notification mails are not received

Notification mails are not received

We are using GitLab Community Edition 11.8.0. Notification mails are not received by any of the project members of a project on https://gitlab.gtd.eu

The email notifications are not received even activating ‘watch’ for the specific project (no notifications for issue creation, delations, comments, …). I have also played with different notification configurations but no notifications are received at all. I have also tried to activate the push notifications and make a push, and nothing.

Do you have any idea of what could be happening?

Thanks,