If you want to send your postcard to an office. Simply type in the FoxRoach Distribution list for that office. Example:
Best practice would be to send the Postcard twice: Once to your contacts and then another time to the office distribution list(s) so that you can remove the OPT OUT message. (By law the opt out message must be present for external email addresses).
To find the correct office distribution list, you can go to Google Mail, click Compose and then select the "To" to to see the FoxRoach Global address book.