To send multiple versions of an email to a single email address, you cannot have the email field as the database's unique identifier, as duplicates cannot exist. If the email field is the database's unique identifier, then you must create a different database with either a different field as the unique identifier, a combination of email and other fields as the combined unique identifier, or a combination of other fields as the combined unique identifier. These setups allow an email address to be used on multiple records and sent to multiple times.

Sometimes, it is necessary to send multiple versions of a single email at once to a single email address. Examples include:

• Sending details for multiple products that were purchased at once
• Sending to multiple members of a family who share an email address