Login to Real Synch and on your active BoomTown To Sisu Integration, click the ellipsis button on the far right-side of your Integration, and select Integration Options:
The resulting page will display the user login email addresses of the Agents enabled for the Integration:
If the Agent appears in the list but is not selected, select the Agent and click Save and Close:
If the Agent does not appear in the list, this means the email address for the Agent is different between BoomTown and Sisu. You will need to update the email address in each platform to make them match exactly. Once the email addresses match, click Update Agents List and then repeat the step above to select the Agent.
Finally, always make sure a given Lead in BoomTown has an email address. This is required for the integration to work (even if you have to give the Lead a fake email address):