CM4SF_TOO_MANY_QUEUEABLES

This is an information message only. A smart email cannot be sent via a Queueable process due to a Salesforce governor limit (i.e. Queueable Jobs). The smart email item will be automatically added to the batch queue process and no further action is required (the batch process may take a little longer to process).It may be worth checking out why your Salesforce org has so many queuable items running as it could be causing other issues (unrelated to the integration). A good place to start is check Apex Logs.More information on Salesforce Queueables can be found here.