Seventh Sense relies on Marketo for the execution of email campaigns. In order to trigger mailings, the list import API is used to enroll contacts into your campaign at the optimal time for each contact.
While the Marketo API is generally reliable, on rare occasions errors due occur. In order to make sure your emails are delivered, in the event of an API error, Seventh Sense will try uploading the contact again until it receives confirmation from Marketo the campaign was executed.
Each time new leads are uploaded to Marketo, Seventh Sense executes the campaign, and any contacts that have already been mailed will be ignored if the campaign is setup up correctly.
Note: It's imperative that all campaigns sent using Seventh Sense have the flow set to only allow leads to run through once a shown below. If leads can run through the campaign more than once, they WILL receive duplicate mailings.
The chart below shows how campaigns work under normal operation:
In the event of a list import failure, Seventh Sense will try to import the contact again until it receives confirmation from Marketo that the import was successful. This process is shown below.
If a campaign is stalled, and you would like to send the campaign immediately in a single blast, you can do so by following the steps outlined in this article.