Out of the box, Mercury SMS provides SMS Opt Out on the Lead and Contact Objects. You can expand this logic to any other Standard or Custom Object within Salesforce.
To configure the Opt Out Process for an Object, you need to create a Checkbox field on the Object, ensuring it is labelled as follows:
Field Name: SMS Opt Out
API Name: SMS_Opt_Out__c
When an inbound message is received containing the phrase ‘STOP’ any ‘SMS Opt Out’ field across any Object will be updated to TRUE, preventing you from sending any further outbound messages to that record.