If you are a G Suite admin, consider the following best practices to generally improve security:

if you are a G Suite admin, consider the following best practices to generally improve security:

• Review and verify current OAuth API access by third-parties.
• Run OAuth Token audit log reports to catch future inadvertent scope grants and set up automated email alerts in the Admin console using the custom alerts feature, or script it with the Reports API.
• Turn on 2-step verification for your organization and use security keys.
• Follow the security checklist if you feel that an account may be compromised.
• Help prevent abuse of your brand in phishing attacks by publishing a DMARCpolicy for your organization.
• Use and enforce rules for S/MIME encryption