I'm writing in response to a query that was raised internally by our COO (also a previous MixPanel customer in another life). We have our Mixpanel environment integrated with OneSignal to send emails automatically to some cohorts of users. Our main question is: what, if any, guarantees do you provide in relation to the delivery of those emails? Is there any audit trail, and visibility to guarantee that at least OneSignal servers receive the cohorts of users in a reliable way? How do you know that all the email addresses exported belong to real users? Anecdotally, we have heard of a number of cases where emails are simply not observed by our customers. We have a total of 893k users tracked in Mixpanel, but only 112K were exported to OneSignal and received our last email. Many thanks in advance for your detailed response,
