How to Enable Emails in Sandbox Environments

Problem

Emails cannot be sent from sandbox or UAT environments. Email records may show status ‘Rendered’ but never send, or errors may include ‘Failed to resolve’ DNS errors pointing to the courier staging API. This typically occurs after a sandbox refresh.

What We Found

By default, email sending is disabled in sandbox environments to prevent accidental emails to real suppliers or customers during testing. After a sandbox refresh, this setting resets to disabled. The setting ‘Enable Emails in Sandbox’ in App Settings controls whether emails can be sent from non-production environments.

Solution

1. Navigate to Setup in your Salesforce sandbox
2. Search for ‘Custom Settings’ in the Quick Find box
3. Find ‘App Settings’ in the list and click ‘Manage’
4. Click ‘Edit’ on the App Settings record
5. Find the checkbox ‘Enable Emails in Sandbox’ and check it to enable
6. Click ‘Save’
7. Attempt to send the email again - it should now send successfully

Notes

• This setting resets to unchecked (disabled) every time you refresh your sandbox
• Production environments do not require this setting - it only applies to sandboxes
• If you have multiple sandbox environments (UAT, Dev, Full Copy), you need to enable this setting in each one separately
• The setting controls whether Kaptio emails route through the email service (SendGrid)

Warnings

⚠️ Once enabled, emails WILL be sent to actual recipients - ensure you are testing with appropriate test email addresses or the sandbox email is properly configured

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Source: KHELP-12189