Check your "SPAM" folder if you are on GMAIL or other E-MAIL system like OUTLOOK.
3DLibre follows the protocol to be recognized as a serious website using Let's Encrypt for the encryption (you know that S on HTTPS) and the method to avoid falling in the SPAM folder, known as SPF, but not all companies recognize it yet or there's something wrong with my setup.
(working on my SPF DNS record !)