Whenever you create or refresh a partial copy or full sandbox, you should be aware of certain privacy settings. For example, you wouldn’t want to accidentally send an email to a contact from a sandbox.
When a sandbox is updated, the email deliverability setting is automatically set to “System email only”. This can be found in Setup > Email > Deliverability > Access to Send Email (All Email Services).
This default setting helps avoid sending certain emails. But sometimes you want to set this setting to “All email”, so you can accurately test email functionality.
Before doing so, it’s recommended to update the email address for all contacts to something generic, like “test@email.com”. Although this requires a data fix, it’s worth the small effort.
Then you simply update the email addresses of the contact’s you want to test with.
The takeaway
Keeping certain contact data private in a testing environment is a good idea for many reasons. Aside from not accidentally sending emails, consider altering addresses and phone numbers so that testers don’t access information they don’t need to access.