One of the manadates of Guest Privacy Policies such as with GDPR, is to ensure that the Marketing OptIn is defaulted to un-checked. The property must obtain explicit consent form the guest, to add them to their email marketing campaigns. To set the default, go to System Configuration => Property => Preferences => ensure defaults are un-checked:
When creating a new reservation in RoomKeyPMS => the reservation form will respect the settings:

GDS/IDS Integrations
For any GDS/IDS Integrations, the Marketing OptIn is not passed from these booking engines; when the reservation flows into RoomKeyPMS, the default setting will be applied to the reservation. As a best practice recommendation, for some of the integrations, the email/address and other information is not provided from the IDS; the properties should make the best effort upon check in to gather the guests information (especially email) and have then OptIn to the hotels Marketing list.
eRes Reservations
- If Property is showing Marketing OptIn on eRes (For more information on configuring Marketing OptIn for eRes - CLICK HERE) => the selection the guest makes on eRes will flow through to RoomKeyPMS
- If Property is not showing Marketing OptIn on eRes => the Default Marketing OptIn will be respected
- For the General Email OptIn, eRes bookings will respect the default