Email Templates: Update Visualforce Email Templates for Guest Users
Where: This change applies to Salesforce orgs with active public communities, sites, and portals in Enterprise, Performance, Unlimited, and Developer editions.
When: This security policy was released in Spring ’20 and was immediately enforced.
Who: This change applies to Visualforce email templates that target guest users in communities.
How: Add the renderUsingSystemContextWithoutSharing="True" attribute to every Visualforce email template.