About addressing email with a personalization field

You must use a personalization field to specify the email address of the email recipient. The value for this field appears on the To: line of the email header.

Important: The OLT and the Deliver document referenced by a mailing must use the same personalization field to specify the email address of the message recipient.
For details about specifying a personalization field for email address in the OLT, seeDefining the Output List Table (OLT).