To use eMailChef, you must comply with the CAN-SPAM act, the US national standard for sending promotional emails.
As part of the CAN-SPAM requirements, you will need to include a valid postal address in all your emails, preferably in the footer. A link to unsubscribe from your newsletters is also mandatory.
Keep in mind that entering a postal address is not sufficient to perform email marketing legitimately. You can only send messages to recipients who have explicitly given their consent to receive your emails.