Importing contacts via an API

A client of mine is working with developers to set up an API between their booking platform ‘ServiceCEO’ and Infusionsoft. They’ve just performed a round of testing and it’s really strange what happened.

They reported that contacts with invalid or no email address were ‘rejected’ by Infusionsoft when they ran the test. They sent through the list of contacts they used in testing and I found that each of the ones that had no email address actually WERE created but they were created 10 times each.

There were a few contacts with ‘xx’ as the value in their email field that were not created at all so I’m suspecting those actually were rejected.

Does anybody have any idea what this means? It’s kind of difficult feeding back to another team doing this work especially when we have little knowledge of APIs and the importing of contacts using one.