Hi Judith, welcome to the Community!
Assuming an email invitation was sent for a user, and they haven't been removed as a user from Confluence, they can trigger a "fresh" link if they click on an expired one. You can also click Resend invite in the Users list to trigger another email from the administration side.
If you remove an unverified user from your site through the Users list in administration, even a non-expired invitation link will not work to grant access to your site.
Hope that helps!
Daniel | Atlassian Support
👋 Hi there, a few of us at Atlassian would love to learn about how you use "space settings" functionality in Confluence. A facelift to the space settings is long overdue and we want to start with im...
Connect with like-minded Atlassian users at free events near you!Find an event
Connect with like-minded Atlassian users at free events near you!
Unfortunately there are no Community Events near you at the moment.Host an event
You're one step closer to meeting fellow Atlassian users at your local event. Learn more about Community Events