Your Box account is blocking invitations to external email addresses like Gmail because your administrator has likely enabled external collaboration restrictions based on a domain "allowlist" (whitelist). To fix this, as an administrator, go to your Box Admin Console, then Enterprise YourTexasBenefits com Settings, look for Content & Sharing or Collaboration settings, and locate the "External collaboration" option. There, you'll probably find a "Limit collaboration to allowlisted domains" setting, where you can manage and add the gmail.com domain (and any other external domains) to the allowed list.