certN uses a password-less authentication system for increased security. In this system, instead of storing a username/email-address and a password for your authentication, only your email address will be stored, and each time you want to log in, a login link and a code will be sent to you, using which you can log in to the system.
If you don’t receive the login emails from email@example.com,
If the steps above don’t work for you, it means that your mail server thinks that the email is spam, and therefore, is deleting or rejecting it. Solving this issue depends on your mail server: You may have access to whitelist firstname.lastname@example.org, or you may have to ask your sysadmin to do it for you.
If you can’t fix the issue in your mail server, the only solution is to use an alternative email address. In contrast to some [poorly set up] corporate email systems, public email services such as those from Gmail and Yahoo usually work without any issues.
There can be two reasons for that: