Mailfloss is an email verification and email cleansing service. By integrating Mailfloss with DailyStory unverified emails for contacts will automatically get cleansed. And, unverifiable emails are prevented from sending.
Mailfloss integration with DailyStory requires several steps.
Obtain a API key for Mailfloss. Note, this requires you to have a commercial account with Mailfloss. You can find your API key here:

Navigate to Account Settings > Integrations and select Mailfloss. Enter the API key obtained in step 1 and click the "Save" button:

Once Mailfloss integration is enabled DailyStory: