How do I clear picklist values in Campaign Monitor?

If you have mapped a Salesforce picklist or multi-select picklist field the selected value(s) will be updated on the corresponding Campaign Monitor field.

If the value(s) are subsequently cleared in Salesforce by default we will not update Campaign Monitor.  This is to ensure the information is preserved in Campaign Monitor.  You can change this behaviour via the import wizard so that when a picklist or multi-select picklist is cleared in Salesforce it will also be cleared in Campaign Monitor.

The option to clear blank values can be found on the final step of the import wizard.  On the scheduling step, you will notice an advanced section. Click to expand and then select Clear blank values. 

The next time the wizard runs, and should a Salesforce picklist or multi-select picklist be empty the update process will clear the corresponding field in Campaign Monitor.