In regards to emails with personalization, the testing practices are the same as all deliveries. Preview the delivery, and send yourself a proof. For the the data coming from an external file or DB, there isn't anything specific but I would recommend validating your data before, during the import process (review the workflow transitions), and after to confirm that everything was imported as expected.
In regards to emails with personalization, the testing practices are the same as all deliveries. Preview the delivery, and send yourself a proof. For the the data coming from an external file or DB, there isn't anything specific but I would recommend validating your data before, during the import process (review the workflow transitions), and after to confirm that everything was imported as expected.