The main cause for this is usually two-fold.

  • You asked TeamUnify to change your URL on the bottom of your invitations and emails to point to your actual domain name instead of the TeamUnify URL, and
  • You have a forward on your domain name instead of redirecting the named servers.

Let Support know about this issue and they will help you to resolve (click the Need Help? tab on the right of your TU site, then click Contact Help).