Your colleague has an upcoming product launch. They heard from the marketing operations team that they cannot go live with the launch email because the instructions provided are missing a required element.
The message created already has the following elements;
* a subscription center link
* a physical address
* a valid from name and from address
* an HTML body
* a plain text version
The instructions told the marketing operations team to use {{contact.emailddress1}} in the "To" field. All videos and images were present in the library, and there are no dynamic expressions in the email.
You need to help identify the missing element.
What should also be included in the instructions?