If your company uses several email domains, you can add all of them, so anyone with an email from any of those domains can join your workspace, or be added automatically when they sign up.
Go to Settings → General.
Click + next to domains.
Enter the domain name you want to add and an email with that domain.
Enter the code sent to that email.
Once a domain is added your workspace, people with emails from that domain can be added to your workspace.